update flatpak github actions

Author: NikolasK-source

.github/workflows/flatpak_release.yml

@@ -7,11 +7,11 @@ jobs:
     name: "Flatpak"
     runs-on: ubuntu-latest
     container:
-      image: bilelmoussaoui/flatpak-github-actions:freedesktop-21.08
+      image: bilelmoussaoui/flatpak-github-actions:freedesktop-23.08
       options: --privileged
     steps:
     - uses: actions/checkout@v2
-    - uses: bilelmoussaoui/flatpak-github-actions/flatpak-builder@v4
+    - uses: bilelmoussaoui/flatpak-github-actions/flatpak-builder@v6
       name: "Build"
       with:
         bundle: modbus-tcp-client-shm.flatpak

.github/workflows/flatpak_test.yml

@@ -6,7 +6,7 @@ jobs:
     name: "Flatpak"
     runs-on: ubuntu-latest
     container:
-      image: bilelmoussaoui/flatpak-github-actions:freedesktop-21.08
+      image: bilelmoussaoui/flatpak-github-actions:freedesktop-23.08
       options: --privileged
     steps:
     - uses: actions/checkout@v2
@@ -20,7 +20,7 @@ jobs:
     - name: Update submodules
       run: git submodule update
 
-    - uses: bilelmoussaoui/flatpak-github-actions/flatpak-builder@v4
+    - uses: bilelmoussaoui/flatpak-github-actions/flatpak-builder@v6
       name: "Build"
       with:
         bundle: test_modbus-tcp-client-shm.flatpak