cli: update backend eslint config to allow __dirname in tests

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/smart-seahorses-ring.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Update default backend ESLint configuration to allow usage of `__dirname` in tests.

packages/cli/config/eslint.backend.js

@@ -14,6 +14,15 @@
  * limitations under the License.
  */
 
+const globalRestrictedSyntax = [
+  {
+    message:
+      'Default import from winston is not allowed, import `* as winston` instead.',
+    selector:
+      'ImportDeclaration[source.value="winston"] ImportDefaultSpecifier',
+  },
+];
+
 module.exports = {
   extends: [
     '@spotify/eslint-config-base',
@@ -69,17 +78,12 @@ module.exports = {
     // Avoid default import from winston as it breaks at runtime
     'no-restricted-syntax': [
       'error',
-      {
-        message:
-          'Default import from winston is not allowed, import `* as winston` instead.',
-        selector:
-          'ImportDeclaration[source.value="winston"] ImportDefaultSpecifier',
-      },
       {
         message:
           "`__dirname` doesn't refer to the same dir in production builds, try `resolvePackagePath()` from `@backstage/backend-common` instead.",
         selector: 'Identifier[name="__dirname"]',
       },
+      ...globalRestrictedSyntax,
     ],
   },
   overrides: [
@@ -103,6 +107,7 @@ module.exports = {
             bundledDependencies: true,
           },
         ],
+        'no-restricted-syntax': ['error', ...globalRestrictedSyntax],
       },
     },
   ],