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](https://github.com/seanmiddleditch/gha-setup-ninja/compare/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>

.github/workflows/build.yml

@@ -135,7 +135,7 @@ jobs:
           submodules: recursive
 
       - name: Install Ninja
-        uses: seanmiddleditch/gha-setup-ninja@v5
+        uses: seanmiddleditch/gha-setup-ninja@v6
 
       - name: Install Clang
         if: "${{ matrix.platform == 'Linux x86_64 Clang' }}"