Updates .NET SDK version for MAUI workloads

Updates the .NET SDK version used for installing MAUI workloads in the beta and production NuGet workflows.

- Ensures the correct .NET SDK version is used for MAUI workload installation.
- Simplifies the workflow by using environment variables.

Author: michaelstonis

.github/workflows/nuget-beta.yml

@@ -12,6 +12,7 @@ env:
     DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
     DOTNET_NOLOGO: true
     NuGetDirectory: ${{ github.workspace}}/nuget
+    DotnetVersion: '9.0.304'
 
 jobs:
     build:
@@ -23,10 +24,10 @@ jobs:
                   fetch-depth: 0  # Fetch full history for release notes generation
             - uses: actions/setup-dotnet@v3
               with:
-                  dotnet-version: "9.x"
+                  dotnet-version: "${{ env.NuGetDirectory }}"
 
             - name: Install MAUI Workloads
-              run: dotnet workload install maui --ignore-failed-sources
+              run: dotnet workload install maui --ignore-failed-sources --version ${{ env.NuGetDirectory }}
 
             - name: Semver Parse
               id: version

.github/workflows/nuget-prod.yml

@@ -12,6 +12,7 @@ env:
     DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
     DOTNET_NOLOGO: true
     NuGetDirectory: ${{ github.workspace}}/nuget
+    DotnetVersion: '9.0.304'
 
 jobs:
     build:
@@ -23,10 +24,10 @@ jobs:
                   fetch-depth: 0  # Fetch full history for release notes generation
             - uses: actions/setup-dotnet@v3
               with:
-                  dotnet-version: "9.x"
+                  dotnet-version: "${{ env.NuGetDirectory }}"
 
             - name: Install MAUI Workloads
-              run: dotnet workload install maui --ignore-failed-sources
+              run: dotnet workload install maui --ignore-failed-sources --version ${{ env.NuGetDirectory }}
 
             - name: Semver Parse
               id: version