Limits test: skip duplicate cases when maximum limit == default limit

src/webgpu/api/validation/capability_checks/limits/README.txt

@@ -1,8 +1,5 @@
 Test everything that shouldn't be valid without a higher-than-specified limit.
 
-- x= that limit {default, max supported (if different), lower than default (TODO: if allowed)}
-
 One file for each limit name.
 
-TODO: implement
-TODO: Also test that "alignment" limits require a power of 2.
+TODO: Test that "alignment" limits require a power of 2.

src/webgpu/api/validation/capability_checks/limits/limit_utils.ts

@@ -556,6 +556,10 @@ export class LimitTestsImpl extends GPUTestBase {
       requestedLimit < 0 && limitValueTest === 'underDefault',
       `requestedLimit(${requestedLimit}) for ${this.limit} is < 0`
     );
+    this.skipIf(
+      limitValueTest !== 'atDefault' && requestedLimit === defaultLimit,
+      'The limit value for this case is the same as the default.'
+    );
     return this._getDeviceWithSpecificLimit(requestedLimit, extraLimits, features);
   }