build-aux,CI: Update KDE Flatpak runtime to 6.8

The underlying Freedesktop runtime is now 24.08 with AOM 3.10.x and
libvpx 1.14.x

.github/workflows/build-project.yaml

@@ -249,7 +249,7 @@ jobs:
     env:
       FLATPAK_BUILD_SHARE_PATH: flatpak_app/files/share
     container:
-      image: ghcr.io/flathub-infra/flatpak-github-actions:kde-6.6
+      image: ghcr.io/flathub-infra/flatpak-github-actions:kde-6.8
       options: --privileged
     steps:
       - uses: actions/checkout@v4

.github/workflows/publish.yaml

@@ -62,7 +62,7 @@ jobs:
       YOUTUBE_SECRET: ${{ secrets.YOUTUBE_SECRET }}
       YOUTUBE_SECRET_HASH: ${{ secrets.YOUTUBE_SECRET_HASH }}
     container:
-      image: ghcr.io/flathub-infra/flatpak-github-actions:kde-6.6
+      image: ghcr.io/flathub-infra/flatpak-github-actions:kde-6.8
       options: --privileged
     strategy:
       matrix:

build-aux/com.obsproject.Studio.json

@@ -1,7 +1,7 @@
 {
     "id": "com.obsproject.Studio",
     "runtime": "org.kde.Platform",
-    "runtime-version": "6.6",
+    "runtime-version": "6.8",
     "sdk": "org.kde.Sdk",
     "command": "obs",
     "finish-args": [
@@ -31,7 +31,7 @@
         },
         "org.freedesktop.LinuxAudio.Plugins": {
             "directory": "extensions/Plugins",
-            "version": "23.08",
+            "version": "24.08",
             "add-ld-path": "lib",
             "merge-dirs": "vst",
             "subdirectories": true,