Update Forgejo CI workflows to use full GitHub action URLs

.forgejo/workflows/ci.yml

@@ -13,10 +13,10 @@ jobs:
   changes:
     runs-on: docker
     steps:
-      - uses: actions/checkout@v4
+      - uses: https://github.com/actions/checkout@v4
 
       - id: filter
-        uses: dorny/paths-filter@v3
+        uses: https://github.com/dorny/paths-filter@v3
         with:
           filters: |
             backend:
@@ -38,9 +38,9 @@ jobs:
     container:
       image: forgejo.okit.pl/oskar/ci-gradle-node:8.7-jdk17
     steps:
-      - uses: actions/checkout@v4
+      - uses: https://github.com/actions/checkout@v4
 
-      - uses: actions/cache@v4
+      - uses: https://github.com/actions/cache@v4
         with:
           path: |
             /home/gradle/.gradle/caches
@@ -60,9 +60,9 @@ jobs:
     container:
       image: forgejo.okit.pl/oskar/ci-flutter-node:stable
     steps:
-      - uses: actions/checkout@v4
+      - uses: https://github.com/actions/checkout@v4
 
-      - uses: actions/cache@v4
+      - uses: https://github.com/actions/cache@v4
         with:
           path: |
             /root/.pub-cache