chore: update actions/cache action

Author: hauleth

.github/workflows/erlang.yml

@@ -17,7 +17,7 @@ jobs:
         otp-version: ${{ matrix.otp_version }}
         rebar3-version: '3.24'
     - name: Restore dependencies cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: deps
         key: ${{ runner.os }}-otp-${{ matrix.otp_version }}-mix-${{ hashFiles('**/rebar.lock') }}