build(deps): bump seanmiddleditch/gha-setup-ninja from 5 to 6

Bumps [seanmiddleditch/gha-setup-ninja](https://github.com/seanmiddleditch/gha-setup-ninja) from 5 to 6.
- [Release notes](https://github.com/seanmiddleditch/gha-setup-ninja/releases)
- [Commits](seanmiddleditch/gha-setup-ninja@v5...v6)

---
updated-dependencies:
- dependency-name: seanmiddleditch/gha-setup-ninja
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -235,7 +235,7 @@ jobs:
 
       - name: Install ninja-build tool for aws-lc-fips-sys on Windows
         if: runner.os == 'Windows'
-        uses: seanmiddleditch/gha-setup-ninja@v5
+        uses: seanmiddleditch/gha-setup-ninja@v6
 
       - name: cargo test (${{ matrix.mode }}, ${{ matrix.features }})
         run: cargo test --locked ${{ matrix.features }} ${{ matrix.mode }} -- --ignored