Fix GitHub Actions deprecation warnings

Author: vslavik

.github/workflows/check-translations.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Install GNU gettext
       run: sudo apt-get install gettext

.github/workflows/ci.yml

@@ -95,7 +95,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: build-linux
     steps:
-      - uses: actions/download-artifact@v2
+      - uses: actions/download-artifact@v3
         with:
           name: source-tarball