Add github actions for building recipes

Author: kristofvc

.github/workflows/flex-cleanup.yml

@@ -0,0 +1,13 @@
+name: Cleanup Flex testing endpoint
+
+on:
+    pull_request_target:
+        types: [ closed ]
+
+defaults:
+    run:
+        shell: bash
+
+jobs:
+    call-flex-cleanup:
+        uses: symfony/recipes/.github/workflows/callable-flex-cleanup.yml@main

.github/workflows/flex-update.yml

@@ -0,0 +1,17 @@
+name: Update Flex endpoint
+
+on:
+    push:
+        branches:
+            - main
+
+defaults:
+    run:
+        shell: bash
+
+jobs:
+    call-flex-update:
+        uses: symfony/recipes/.github/workflows/callable-flex-update.yml@main
+        with:
+            branch: main
+            contrib: true