Add git build and test steps back

Don't try to install cygport again.  That's a bad idea.

.github/workflows/ci.yml

@@ -90,3 +90,55 @@ jobs:
           path: cygport-build-results-${{ matrix.cygport-ref }}.txz
           if-no-files-found: error
         timeout-minutes: 10
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          set-safe-directory: false  # actions/checkout otherwise tries to use the wrong config file, per actions/checkout#767
+          fetch-depth: 0  # Need this to push to Cygwin Git mirror
+        timeout-minutes: 1
+      - name: Load variables from the cygport file
+        run: |
+          eval "$(cygport git.cygport vars BUILD_REQUIRES PVR)"
+          printf 'BUILD_REQUIRES=%s\n' "$BUILD_REQUIRES" >>"$GITHUB_ENV"
+          printf 'PVR=%s\n' "$PVR" >>"$GITHUB_ENV"
+        timeout-minutes: 1
+      - name: Install Cygwin build requirements
+        uses: cygwin/cygwin-install-action@v2
+        with:
+          packages: ${{ env.BUILD_REQUIRES }}
+        timeout-minutes: 30
+      - name: Generate cygcheck output
+        if: always()
+        run: cygcheck -srv >/var/log/cygcheck.out
+        timeout-minutes: 5
+      - name: Store Cygwin logs
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: cygwin-logs-${{ matrix.cygport-ref }}
+          path: 'C:\cygwin\var\log\'
+        timeout-minutes: 5
+      - name: Cygport download
+        run: cygport git.cygport download
+        timeout-minutes: 5
+      - name: Cygport prep
+        run: cygport git.cygport prep
+        timeout-minutes: 1
+      - name: Cygport compile
+        run: cygport git.cygport compile
+        timeout-minutes: 30
+      - name: Cygport test
+        run: cygport git.cygport test
+        timeout-minutes: 300
+      - name: Tar up build results
+        if: always()
+        run: tar -caf git-build-results.txz git-*-*.*/
+        timeout-minutes: 10
+      - name: Store build results
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: build-results-${{ matrix.cygport-ref }}
+          path: git-build-results.txz
+          if-no-files-found: error
+        timeout-minutes: 5

build-requires.txt

@@ -1,7 +1,6 @@
 asciidoc
 bash-completion
 bash-completion-devel
-cygport
 dblatex
 gcc-core
 gettext