Use official .NET install script instead of nixpkgs

nixpkgs only has .NET 10 preview, use Microsoft's install script for stable.

💘 Generated with Crush

Assisted-by: Claude Opus 4.5 via Crush <crush@charm.land>

.forgejo/workflows/release.yml

@@ -11,7 +11,12 @@ jobs:
     runs-on: default
     steps:
       - name: Install dependencies
-        run: nix-env -iA nixpkgs.nodejs nixpkgs.dotnet-sdk_10 nixpkgs.openssh nixpkgs.git
+        run: |
+          nix-env -iA nixpkgs.nodejs nixpkgs.openssh nixpkgs.git nixpkgs.curl nixpkgs.icu
+          curl -sSL https://dot.net/v1/dotnet-install.sh | bash -s -- --channel 10.0
+          echo "$HOME/.dotnet" >> $GITHUB_PATH
+          export PATH="$HOME/.dotnet:$PATH"
+          dotnet --version
 
       - name: Checkout
         uses: actions/checkout@v4
@@ -28,6 +33,7 @@ jobs:
 
       - name: Build all platforms
         run: |
+          export PATH="$HOME/.dotnet:$PATH"
           # Windows
           dotnet publish -c Release -r win-x64 -o dist/win-x64/standard
           dotnet publish -c Release -r win-x64 -p:EmbeddedApk=delver.apk -o dist/win-x64/embedded