fix(@angular/build): warn about unsupported options in the unit-test karma runner

The karma runner silently ignored `providersFile`, `outputFile` and `coverageReporters`.
For example, `ng test --runner karma --coverage --coverage-reporters lcov` wrote no `lcov.info`
and printed nothing. Log the same "not supported" warning that the runner already logs for its
other unsupported options.

Author: MeAkib

packages/angular/build/src/builders/unit-test/runners/karma/executor.ts

@@ -53,6 +53,24 @@ export class KarmaExecutor implements TestExecutor {
       );
     }
 
+    if (unitTestOptions.providersFile) {
+      context.logger.warn(
+        'The "karma" test runner does not support the "providersFile" option. The option will be ignored.',
+      );
+    }
+
+    if (unitTestOptions.outputFile) {
+      context.logger.warn(
+        'The "karma" test runner does not support the "outputFile" option. The option will be ignored.',
+      );
+    }
+
+    if (unitTestOptions.coverage?.reporters) {
+      context.logger.warn(
+        'The "karma" test runner does not support the "coverageReporters" option. The option will be ignored.',
+      );
+    }
+
     const buildTargetOptions = (await context.validateOptions(
       await context.getTargetOptions(unitTestOptions.buildTarget),
       await context.getBuilderNameForTarget(unitTestOptions.buildTarget),