Update GitHub workflows to point to shared workflows.

Author: jpe7s

.github/workflows/build.yml

@@ -0,0 +1,13 @@
+name: Gradle Check
+
+on:
+  push:
+    branches:
+      - main
+  pull_request_target:
+    types: [ opened, synchronize ]
+
+jobs:
+  build:
+    uses: sava-software/sava-build/.github/workflows/build.yml@main
+    secrets: inherit

.github/workflows/gradle.yml

@@ -0,0 +1,14 @@
+name: Publish Release
+
+on:
+  create:
+    tags:
+      - '\d+\.\d+\.\d+'
+
+jobs:
+  publish:
+    uses: sava-software/sava-build/.github/workflows/publish.yml@main
+    secrets: inherit
+    permissions:
+      contents: read
+      packages: write