Use specific sha commit from darker repos which resolves current issue. Change to new version which contains the fix when applicable.

.github/workflows/darker.yml

@@ -14,7 +14,9 @@ jobs:
         with:
           fetch-depth: 0
       - uses: actions/setup-python@v4
-      - uses: akaihola/darker@1.4.2
+        with:
+          python-version: '3.7'
+      - uses: akaihola/darker@1.5.1
         with:
           options: "--check --diff --isort"
-          version: "1.4.2"
+          version: "@3c675b009d747cadd6e8048d2c57a5b1cd54fb3e"

.pre-commit-config.yaml

@@ -39,7 +39,7 @@ repos:
       - id: check-vcs-permalinks
 
   - repo: https://github.com/akaihola/darker
-    rev: 1.4.2
+    rev: 3c675b009d747cadd6e8048d2c57a5b1cd54fb3e
     hooks:
     -   id: darker
         args: [--isort]