pre-commit: add oxipng for lossless PNG compression (#362)

Author: jbampton

.github/workflows/lint.yml .github/workflows/pre-commit.yml.github/workflows/lint.yml renamed to .github/workflows/pre-commit.yml

@@ -15,7 +15,7 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-name: Lint
+name: pre-commit
 
 on: [pull_request]
 
@@ -45,3 +45,5 @@ jobs:
           key: pre-commit|${{ env.PY }}|${{ hashFiles('.pre-commit-config.yaml') }}
       - name: Run pre-commit
         run: pre-commit run --all-files
+      - name: Run manual pre-commit hooks
+        run: pre-commit run --all-files --hook-stage manual

.pre-commit-config.yaml

@@ -26,6 +26,12 @@ repos:
     hooks:
       - id: identity
       - id: check-hooks-apply
+  - repo: https://github.com/oxipng/oxipng
+    rev: v9.1.5
+    hooks:
+      - id: oxipng
+        args: ['--fix', '-o', '4', '--strip', 'safe', '--alpha']
+        stages: [manual]
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v5.0.0
     hooks: