ci: upgrade cache action to v5 (#7)

- replace actions/cache@v4 with @v5 in CI workflow\n- remove remaining Node20 deprecation warning source from cache steps

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: LessUp

.github/workflows/ci.yml

@@ -40,7 +40,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Cache CMake dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             build/debug/_deps
@@ -75,7 +75,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Cache CMake dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             build/release/_deps
@@ -107,7 +107,7 @@ jobs:
         uses: actions/checkout@v5
 
       - name: Cache CMake dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             build/release/_deps