Update cache action for CI

Author: NattyNarwhal

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Cache DB2 library
         id: cache-clidriver
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: clidriver
           key: ${{ runner.os }}-clidriver
@@ -113,7 +113,7 @@ jobs:
         uses: actions/checkout@v3
       - name: Cache DB2 library
         id: cache-clidriver
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: clidriver
           key: ${{ runner.os }}-clidriver