ci: add build and deploy workflow for magic-link jar

.github/workflows/build.yml

@@ -0,0 +1,48 @@
+name: "Keycloak magic-link build"
+
+on:
+    workflow_dispatch:
+    push:
+        branches:
+            - "main"
+            - "production"
+
+concurrency:
+    group: ${{ github.workflow }}-${{ github.ref_name }}
+    cancel-in-progress: true
+
+jobs:
+    build:
+        name: Build
+        runs-on: [ self-hosted, java21 ]
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+
+            - name: Setup Java 21
+              run: |
+                export JAVA_HOME=/usr/lib/jvm/bellsoft-java21-full-amd64
+                export PATH=$JAVA_HOME/bin:$PATH
+                echo "JAVA_HOME=$JAVA_HOME" >> $GITHUB_ENV
+                echo "$JAVA_HOME/bin" >> $GITHUB_PATH
+                echo "Java version being used:"
+                java -version
+                echo "Maven version being used:"
+                mvn -version
+
+            - name: Maven Build
+              run: mvn clean package -Dmaven.repo.local=${{ github.workspace }}/.m2/repository
+
+            - name: Upload jar to integration
+              if: github.ref_name == 'main'
+              run: |
+                mc mb ostore/keycloak/integration --ignore-existing
+                mc rm --recursive --force ostore/keycloak/integration/keycloak-magic-link- || true
+                find . -path "*/target/keycloak-magic-link-*.jar" | xargs -I {} mc cp {} ostore/keycloak/integration/
+
+            - name: Upload jar to production
+              if: github.ref_name == 'production'
+              run: |
+                mc mb ostore/keycloak/production --ignore-existing
+                mc rm --recursive --force ostore/keycloak/production/keycloak-magic-link- || true
+                find . -path "*/target/keycloak-magic-link-*.jar" | xargs -I {} mc cp {} ostore/keycloak/production/