🚦 Use forked github actions

This project was previously using 3rd-party Github actions, some of
which were effectively abandonware that was resulting in Github
deprecation warnings.

I've forked all 3rd-party projects, made local changes as needed, and
updated the references here to refer only to my own copies which I shall
maintain from now on.

.github/actions/prepare-runner/action.yaml

@@ -78,7 +78,7 @@ runs:
     # Vulkan
 
     - name: Install Vulkan SDK
-      uses: humbletim/[email protected].0
+      uses: bitwizeshift/[email protected].1
       if: runner.os == 'Linux' || runner.os == 'Windows'
       with:
         vulkan-query-version: 1.3.204.0

.github/actions/rust-toolchain/action.yaml

@@ -19,7 +19,7 @@ runs:
   using: "composite"
   steps:
     - name: Prepare Cache
-      uses: Swatinem/rust-cache@v2
+      uses: bitwizeshift/action-rust-cache@v2
       with:
         shared-key: ${{ inputs.cache-key }}