ci: isolate oauth example compile cache

Author: szTheory

.github/workflows/ci.yml

@@ -550,7 +550,7 @@ jobs:
           path: |
             test/example/deps
             test/example/_build
-          key: ${{ runner.os }}-example-dev-${{ hashFiles('test/example/mix.lock', 'test/example/config/**', 'test/example/lib/**/*.ex', 'lib/**/*.ex', 'mix.exs') }}
+          key: ${{ runner.os }}-example-dev-oauth-test-routes-v1-${{ hashFiles('test/example/mix.lock', 'test/example/config/**', 'test/example/lib/**/*.ex', 'lib/**/*.ex', 'mix.exs') }}
       - name: Fetch example deps
         working-directory: test/example
         env:
@@ -560,7 +560,9 @@ jobs:
         working-directory: test/example
         env:
           MIX_ENV: dev
-        run: mix compile --warnings-as-errors
+        run: |
+          mix clean
+          mix compile --warnings-as-errors
       - name: Setup example dev DB
         working-directory: test/example
         env: