Move CI to GitHub actions

This commit moves the regular build and snapshot deployment to GitHub
actions, based on a standard actions that are reusable.

Closes gh-447

.github/workflows/build-pull-request.yml

@@ -0,0 +1,24 @@
+name: Build Pull Request
+on: pull_request
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build Pull Request
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'spring-projects/spring-retry' }}
+    steps:
+      - name: Set Up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'liberica'
+      - name: Check Out
+        uses: actions/checkout@v4
+      - name: Build
+        run: ./mvnw --batch-mode --update-snapshots verify
+      - name: Print JVM Thread Dumps When Cancelled
+        uses: ./.github/actions/print-jvm-thread-dumps
+        if: cancelled()