ci: make windows-latest a hard-fail job (drop continue-on-error)

Now that the .miserc.toml TOML-literal fix makes Windows pass, remove the
windows-only continue-on-error so the job genuinely blocks on failure and
can be promoted to a required status check in branch protection.

Author: srinitude

.github/workflows/quality.yml

@@ -13,7 +13,6 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
-    continue-on-error: ${{ matrix.os == 'windows-latest' }}
     steps:
       - uses: actions/checkout@v4