ci: delete rocks caching

Since the installation of rocks takes not much time, so its caching can
be removed.

Author: themilchenko

.github/workflows/testing.yaml

@@ -42,13 +42,6 @@ jobs:
         with: 
           tarantool: ${{ matrix.tarantool }}
 
-      - name: Cache rocks
-        uses: actions/cache@v3
-        id: cache-rocks
-        with:
-          path: .rocks/
-          key: "cache-rocks-${{ matrix.tarantool }}${{ env.VERSION_POSTFIX }}"
-
       - name: Install requirements
         run: make deps depname=test
         if: steps.cache-rocks.outputs.cache-hit != 'true'
@@ -87,13 +80,6 @@ jobs:
         with: 
           tarantool: '3.3'
 
-      - name: Cache rocks
-        uses: actions/cache@v3
-        id: cache-rocks
-        with:
-          path: .rocks/
-          key: "cache-rocks-3.1${{ env.VERSION_POSTFIX }}"
-
       - name: Install requirements
         run: make deps depname=coverage
         if: steps.cache-rocks.outputs.cache-hit != 'true'