.github: add PR test

Add a PR testing workflow where we can start to add autotests.

At the moment, it just checks that the Makefile workflows function, but
it could be expanded to include unit tests and (if we get a NILRT
runner) integration tests.

Signed-off-by: Alex Stewart <[email protected]>

.github/workflows/pr-test.yml

@@ -0,0 +1,45 @@
+name: PR Testing
+
+on: [pull_request]
+
+jobs:
+  make-workflows:
+    runs-on: ubuntu-latest
+
+    env:
+      DESTDIR: /tmp/nilrt-snac
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Fetch all history so that git-describe works
+      - run: make all
+      - name: make install
+        run: |
+          make install
+          tree -ap "${DESTDIR}"
+      - name: make uninstall
+        run: |
+          make uninstall
+          tree -ap "${DESTDIR}"
+          
+          leftover_files=false
+          find "${DESTDIR}" -type f >./leftover_files
+          
+          while read file; do
+            echo "ERROR: leftover file: ${file}"
+            leftover_files=true
+          done <./leftover_files
+
+          if $leftover_files; then
+            echo "ERROR: uninstall did not remove all files."
+            cat ./leftover_files
+            exit 1
+          else
+            echo "OK"
+          fi
+      - name: make dist
+        run: |
+          make dist
+          tar --list -f ./nilrt-snac-*.tar.gz