Update deprecated GitHub Workflows

.github/workflows/flatpak.yml

@@ -8,10 +8,10 @@ jobs:
   flatpak:
     runs-on: ubuntu-latest
     container:
-      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-49
+      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-50
       options: --privileged
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Build Flatpak
       uses: flatpak/flatpak-github-actions/flatpak-builder@v6
       with:

.github/workflows/pyinstaller-linux.yml

@@ -8,7 +8,7 @@ jobs:
   pyinstaller-linux:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       # We shouldn't use actions/setup-python since PyGObject is compiled against the system Python
       - name: Install System Dependencies
         uses: awalsh128/cache-apt-pkgs-action@latest
@@ -24,7 +24,7 @@ jobs:
         run: LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu pyinstaller yafi.spec -- --onefile
         working-directory: pyinstaller
       - name: Upload PyInstaller Artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           path: pyinstaller/dist/YAFI
           name: yafi-linux-${{ github.sha }}

.github/workflows/pyinstaller-windows.yml

@@ -8,15 +8,15 @@ jobs:
   pyinstaller-windows:
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
         with:
             python-version: '3.14'
             cache: 'pip'
 
       - name: Cache GTK4
         id: cache-gtk4
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: C:\gtk
           key: Gvsbuild_2026.2.0
@@ -46,7 +46,7 @@ jobs:
         working-directory: pyinstaller
 
       - name: Upload PyInstaller Artifact (ZIP)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           path: pyinstaller/dist/YAFI/*
           name: yafi-windows-${{ github.sha }}
@@ -56,7 +56,7 @@ jobs:
         working-directory: pyinstaller
 
       - name: Upload PyInstaller Artifact (Standalone)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           path: pyinstaller/dist/YAFI.exe
           name: yafi-windows-standalone-${{ github.sha }}