try to speed up build by using ubuntu assemblies for everything

Author: Lordfirespeed

.github/workflows/build.yml

@@ -8,8 +8,51 @@ on:
   pull_request:  
 
 jobs:
+  grab-reference-assemblies:
+    name: Get reference assemblies from Unity
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fetch Sources
+        uses: actions/checkout@v4
+
+      - name: Cache Unity project
+        uses: actions/cache@v3
+        with:
+          path: ./UnityProject/Library
+          key: Library-UnityNetcodePatcher-linux-x64
+          restore-keys: |
+            Library-UnityNetcodePatcher-
+            Library-
+            
+      - name: Restore Unity project  
+        uses: game-ci/unity-builder@v4
+        env:
+          UNITY_LICENSE: ${{ secrets.UNITY_LICENSE }}
+          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
+          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
+        with:
+          projectPath: ./UnityProject
+          targetPlatform: StandaloneLinux64
+          buildMethod: UnityBuilderAction.RestoreScript.Restore
+          customParameters: -hostPlatform linux
+
+      - name: Tree assembly source paths
+        run: |
+          sudo apt-get install tree
+          tree ./UnityProject/Library/ScriptAssemblies/
+          tree ./UnityProject/UnityEditor
+      
+      - name: Upload assemblies as build artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: reference-assemblies
+          path: |
+            UnityProject/Library/ScriptAssemblies/
+            UnityProject/UnityEditor/
+
   build:
     name: Build for ${{ matrix.target }}
+    needs: grab-reference-assemblies
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -35,38 +78,17 @@ jobs:
           fetch-depth: 0
           filter: tree:0
           submodules: recursive
+      
+      - name: Fetch Reference Assemblies
+        uses: actions/download-artifact@v4
+        with:
+          name: reference-assemblies
+          path: UnityProject/
 
       - uses: actions/setup-dotnet@v3
         with:
           dotnet-version: "8.0.100"
 
-      - name: Cache Unity project   
-        uses: actions/cache@v3
-        with:
-          path: ./UnityProject/Library
-          key: Library-UnityNetcodePatcher-${{ matrix.target }}
-          restore-keys: |
-            Library-UnityNetcodePatcher-
-            Library-
-
-      - name: Restore Unity project  
-        uses: game-ci/unity-builder@v4
-        env:
-          UNITY_LICENSE: ${{ secrets.UNITY_LICENSE }}
-          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
-          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
-        with:
-          projectPath: ./UnityProject
-          targetPlatform: ${{ matrix.unityTarget }}
-          buildMethod: UnityBuilderAction.RestoreScript.Restore
-          customParameters: -hostPlatform ${{ matrix.kind }}
-      
-      - name: Tree assembly source paths  
-        run: |
-          sudo apt-get install tree
-          tree ./UnityProject/Library/ScriptAssemblies/
-          tree ./UnityProject/UnityEditor
-          
       - name: Build solution
         shell: bash
         run: |