Add CI using bitcoin-maintainer-tools

I cannot get MSRV to build at the moment no matter what pinning I try.

So this is like normal but no MSRV job, also removes `bitcoind` from the
workspace so that `run_task` works because `bitcoind` features are
non-standard.

.github/workflows/rust.yaml

@@ -0,0 +1,181 @@
+---   # rust-bitcoin CI: If you edit this file please update README.md
+on:   # yamllint disable-line rule:truthy
+  push:
+    branches:
+      - master
+      - 'test-ci/**'
+  pull_request:
+
+name: Continuous integration
+
+jobs:
+  Prepare:
+    runs-on: ubuntu-latest
+    outputs:
+      nightly_version: ${{ steps.read_toolchain.outputs.nightly_version }}
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Read nightly version"
+        id: read_toolchain
+        run: echo "nightly_version=$(cat nightly-version)" >> $GITHUB_OUTPUT
+
+  Stable:                       # 2 jobs, one per manifest.
+    name: Test - stable toolchain
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        dep: [minimal, recent]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Checkout maintainer tools"
+        uses: actions/checkout@v4
+        with:
+          repository: rust-bitcoin/rust-bitcoin-maintainer-tools
+          rev: b2ac115
+          path: maintainer-tools
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@stable
+      - name: "Set dependencies"
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
+      - name: "Run test script"
+        run: ./maintainer-tools/ci/run_task.sh stable
+
+  Nightly:                      # 2 jobs, one per manifest.
+    name: Test - nightly toolchain
+    needs: Prepare
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        dep: [minimal, recent]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Checkout maintainer tools"
+        uses: actions/checkout@v4
+        with:
+          repository: rust-bitcoin/rust-bitcoin-maintainer-tools
+          rev: b2ac115
+          path: maintainer-tools
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@v1
+        with:
+          toolchain: ${{ needs.Prepare.outputs.nightly_version }}
+      - name: "Set dependencies"
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
+      - name: "Run test script"
+        run: ./maintainer-tools/ci/run_task.sh nightly
+
+  Lint:
+    name: Lint - nightly toolchain
+    needs: Prepare
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        dep: [recent]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Checkout maintainer tools"
+        uses: actions/checkout@v4
+        with:
+          repository: rust-bitcoin/rust-bitcoin-maintainer-tools
+          rev: b2ac115
+          path: maintainer-tools
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@v1
+        with:
+          toolchain: ${{ needs.Prepare.outputs.nightly_version }}
+      - name: "Install clippy"
+        run: rustup component add clippy
+      - name: "Set dependencies"
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
+      - name: "Run test script"
+        run: ./maintainer-tools/ci/run_task.sh lint
+
+  Docs:
+    name: Docs - stable toolchain
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        dep: [recent]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Checkout maintainer tools"
+        uses: actions/checkout@v4
+        with:
+          repository: rust-bitcoin/rust-bitcoin-maintainer-tools
+          rev: b2ac115
+          path: maintainer-tools
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@stable
+      - name: "Set dependencies"
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
+      - name: "Run test script"
+        run: ./maintainer-tools/ci/run_task.sh docs
+
+  Docsrs:
+    name: Docs - nightly toolchain
+    needs: Prepare
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        dep: [recent]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Checkout maintainer tools"
+        uses: actions/checkout@v4
+        with:
+          repository: rust-bitcoin/rust-bitcoin-maintainer-tools
+          rev: b2ac115
+          path: maintainer-tools
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@v1
+        with:
+          toolchain: ${{ needs.Prepare.outputs.nightly_version }}
+      - name: "Set dependencies"
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
+      - name: "Run test script"
+        run: ./maintainer-tools/ci/run_task.sh docsrs
+
+  Integration:                  # 1 job for each bitcoind version we support.
+    name: Integration tests - stable toolchain
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        feature:
+          [
+            "26_0",
+            "25_2",
+            "25_1",
+            "25_0",
+            "24_2",
+            "24_1",
+            "24_0_1",
+            "23_2",
+            "23_1",
+            "23_0",
+            "22_1",
+            "22_0",
+            "0_21_2",
+            "0_20_2",
+            "0_19_1",
+            "0_18_1",
+            "0_17_2",
+          ]
+    steps:
+      - name: "Checkout repo"
+        uses: actions/checkout@v4
+      - name: "Select toolchain"
+        uses: dtolnay/rust-toolchain@stable
+      - name: "Run integration tests"
+        run: cd integration_test && cargo test --features=${{ matrix.feature }}