GithubCI: use nuget source instead of Github

Use nuget source instead of Github packages so that there is
no need for authentication anymore.

Update maui submodule to point to CrossMaui/new branch.

.github/workflows/CI.yml

@@ -241,36 +241,32 @@ jobs:
   linux-github--dotnet-and-mono:
     runs-on: ubuntu-22.04
     env:
-      GtkSharpVersion: 3.24.24.77-develop
-      DotnetVersion: 6.0.300
+      GtkSharpVersion: 3.24.24.95
+      DotnetVersion: 6.0.400
     steps:
     - uses: actions/checkout@v1
       with:
         submodules: true
-    # We also tested using 6.0.111 for both projects
-    # but MAUI failed to build on this version with this error:
-    # Could not load file or assembly 'Microsoft.CodeAnalysis, Version=4.2.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
-    # so instead we use 6.0.300
     - name: Setup .NET SDK ${{ env.DotnetVersion }}
       uses: actions/[email protected]
       with:
         dotnet-version: ${{ env.DotnetVersion }}
     - name: Install gtk workload
       run: |
-        dotnet nuget add source --username ${{ github.repository_owner }} --password ${{ secrets.GITHUB_TOKEN }} --store-password-in-clear-text --name github "https://nuget.pkg.github.com/GtkSharp/index.json"
-        # For some reason automatic workload manifest detection doesn't work (see https://github.com/GtkSharp/GtkSharp/issues/355#issuecomment-1446262239), so download and uzip mainfest file manually
-        wget --user ${{ github.repository_owner }} --password ${{ secrets.GITHUB_TOKEN }} https://nuget.pkg.github.com/GtkSharp/download/gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}/$GtkSharpVersion/gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}.nupkg
+        wget -O gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}.nupkg https://globalcdn.nuget.org/packages/gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}.$GtkSharpVersion.nupkg
         DOTNET_DIR=/home/runner/.dotnet
         WORKLOAD_MANIFEST_DIR=$DOTNET_DIR/sdk-manifests/${{ env.DotnetVersion }}/gtksharp.net.sdk.gtk
+        mkdir -p $WORKLOAD_MANIFEST_DIR/
         unzip -j gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}.nupkg "data/*" -d $WORKLOAD_MANIFEST_DIR/
         rm gtksharp.net.sdk.gtk.manifest-${{ env.DotnetVersion }}.nupkg
+        # otherwise we get System.UnauthorizedAccessException: Access to the path '/home/runner/.dotnet/sdk-manifests/6.0.300/gtksharp.net.sdk.gtk/WorkloadManifest.json' is denied.
         chmod 764 $WORKLOAD_MANIFEST_DIR/*
         dotnet workload search
         dotnet workload install gtk --skip-manifest-update
     - name: Add Maui Nuget source
       run: |
         cd dependencies/maui
-        dotnet nuget add source --username ${{ github.repository_owner }} --password ${{ secrets.GITHUB_TOKEN }} --store-password-in-clear-text --name github "https://nuget.pkg.github.com/GtkSharp/index.json"
+        dotnet nuget add source --name nuget https://api.nuget.org/v3/index.json
     - name: install missing dependencies
       run: sudo apt install --yes fsharp nunit-console
     - name: check mono version