List our direct dependencies in requirements_vendor.in

Then, using uv, we can build requirements_vendor.txt and remove
various unused dependencies. This isn't perfect, because we want to
vendor everything regardless of markers, and thus this still requires
manual fixup to remove all markers from the output.

This allows us to remove a number of packages (attrs, certifi,
importlib-metadata, more-itertools, pathlib2, and zipp), but does add
a few extra (colorama, which gives pytest better colourized output on
Windows; tomli, which pytest relies on to parse *.toml files on Python
< 3.11; and pyparsing, which packaging relies on to parse markers and
requirements).

tools/pyproject.toml

@@ -9,8 +9,6 @@ protected-files = [
 
 [tool.vendoring.license.fallback-urls]
 atomicwrites = "https://raw.githubusercontent.com/untitaker/python-atomicwrites/refs/tags/1.1.5/LICENSE"
-more_itertools = "https://raw.githubusercontent.com/more-itertools/more-itertools/refs/tags/4.2.0/LICENSE"
-pathlib2 = "https://raw.githubusercontent.com/jazzband/pathlib2/refs/tags/2.3.5/LICENSE.rst"
 webencodings = "https://raw.githubusercontent.com/gsnedders/python-webencodings/refs/tags/v0.5.1/LICENSE"
 
 [tool.vendoring.transformations]

tools/requirements_vendor.in

@@ -0,0 +1,18 @@
+# This lists all the packages we use directly; these are unpinned here as we
+# can rely on the existing pinned versions in requirements_vendor.txt to
+# control when we do upgrades. It also makes this easier to audit, as
+# everything here should see actual usage outside of third_party.
+
+atomicwrites
+h2
+hpack
+html5lib
+hyperframe
+# tooltool is referenced (by path) in tools/wpt/android.py
+mozilla-tooltool-client @ git+https://github.com/mozilla-releng/tooltool.git@c1bda97eda1ec5246aa73a358c5e1d47e222380c#subdirectory=client
+packaging
+pytest-asyncio
+pytest
+pywebsocket3
+six
+websockets

tools/requirements_vendor.txt

@@ -1,22 +1,55 @@
+# This file was autogenerated by uv via the following command:
+#    uv pip compile --universal --python-version 3.8 requirements_vendor.in -o requirements_vendor.txt
+
+# This file was then modified to remove all markers, as we want to make
+# sure everything is always available when it is needed.
+
 atomicwrites==1.1.5  # Update license in pyproject.toml when this changes.
-attrs==23.2.0
-certifi==2018.4.16
+    # via -r requirements_vendor.in
+colorama==0.4.6
+    # via pytest
 exceptiongroup==1.2.1
+    # via pytest
 h2==4.1.0
+    # via -r requirements_vendor.in
 hpack==4.0.0
+    # via
+    #   -r requirements_vendor.in
+    #   h2
 html5lib==1.1
+    # via -r requirements_vendor.in
 hyperframe==6.0.1
-importlib-metadata==2.1.0
+    # via
+    #   -r requirements_vendor.in
+    #   h2
 iniconfig==1.1.1
-more-itertools==4.2.0  # Update license in pyproject.toml when this changes.
+    # via pytest
 mozilla-tooltool-client @ git+https://github.com/mozilla-releng/tooltool.git@c1bda97eda1ec5246aa73a358c5e1d47e222380c#subdirectory=client
+    # via -r requirements_vendor.in
 packaging==21.3
-pathlib2==2.3.5  # Update license in pyproject.toml when this changes.
+    # via
+    #   -r requirements_vendor.in
+    #   pytest
 pluggy==1.5.0
+    # via pytest
+pyparsing==3.1.4
+    # via packaging
 pytest==8.2.1
+    # via
+    #   -r requirements_vendor.in
+    #   pytest-asyncio
 pytest-asyncio==0.19.0
+    # via -r requirements_vendor.in
 pywebsocket3==4.0.2
+    # via -r requirements_vendor.in
 six==1.16.0
+    # via
+    #   -r requirements_vendor.in
+    #   html5lib
+    #   pywebsocket3
+tomli==2.2.1
+    # via pytest
 webencodings==0.5.1  # Update license in pyproject.toml when this changes.
+    # via html5lib
 websockets==12.0
-zipp==1.2.0
+    # via -r requirements_vendor.in