chore(deps): update actions/cache action to v3 (#236)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/elixir.yml

@@ -107,7 +107,7 @@ jobs:
           elixir-version: ${{ matrix.elixir_version }}
           rebar3-version: ${{ matrix.rebar3_version }}
       - name: Cache
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: |
             ~/deps