upgrade actions/cache from v3 to v4

Author: Lordfirespeed

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Cache Unity project
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ./UnityProject/Library
           key: Library-UnityNetcodePatcher-linux-x64

.github/workflows/publish.yml

@@ -13,7 +13,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Cache Unity project
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ./UnityProject/Library
           key: Library-UnityNetcodePatcher-linux-x64