Add Windows CI job with GIX_TEST_IGNORE_ARCHIVES=1

Some of these fail. We report the step as failing if any fail,
which currently at least 14 and usually 15 are expected to (one of
them is a performance test). If more than 15 fail, we'll fail this
job, which will fail the workflow overall, but the job is still
deliberately not treated as a required check for PR auto-merge.

Right now, the expected number of failures is delibreately set too
low, to 13, which is unlikely to be satisfied. This is just to test
the new job. After verifying that it can trigger job failure when
an excessive number of test case failures occurs, and fixing any
readily apparent bugs in the job definition, this value will be
raised, probably to 15.

See GitoxideLabs#1358 for information on the known-failing tests on Windows
with `GIX_TEST_IGNORE_ARCHIVES=1`.

.github/workflows/ci.yml

@@ -80,6 +80,37 @@ jobs:
       - name: Check that tracked archives are up to date
         run: git diff --exit-code  # If this fails, the fix is usually to commit a regenerated archive.
 
+  test-fixtures-windows:
+    runs-on: windows-latest
+    env:
+      # FIXME: Change to 15 after verifying that the last step can fail.
+      # See https://github.com/GitoxideLabs/gitoxide/issues/1358.
+      EXPECTED_FAILURE_COUNT: 13
+    defaults:
+      run:
+        shell: bash  # Includes `-o pipefail`.
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: nextest
+      - name: "Test (nextest)"
+        env:
+          GIX_TEST_IGNORE_ARCHIVES: 1
+        run: |
+          cargo nextest --color=always run --workspace --no-fail-fast |& tee nextest.log
+        continue-on-error: true
+      - name: Allow up to ${{ env.EXPECTED_FAILURE_COUNT }} failures
+        if: failure()
+        run: |
+          set -x
+          sed -Ei 's/\x1B\[[[:digit:];]*m//g' nextest.log  # Remove ANSI color codes.
+          pattern='\n-{10,}\r?\n[ \t]+Summary\b[^\n]+[ \t]\K\d+(?= failed\b)'
+          count="$(grep -zoP "$pattern" nextest.log)"
+          ((count <= EXPECTED_FAILURE_COUNT))
+
   test-32bit:
     runs-on: ubuntu-latest
     strategy: