call describeBehaviorOfERC165 in spec test

Author: 0xCourtney

spec/token/common/ERC2981.behavior.ts

@@ -1,3 +1,4 @@
+import { describeBehaviorOfERC165 } from '../../introspection';
 import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers';
 import { describeFilter } from '@solidstate/library';
 import { ERC2981Mock } from '@solidstate/typechain-types';
@@ -24,6 +25,14 @@ export function describeBehaviorOfERC2981(
       instance = await deploy();
     });
 
+    describeBehaviorOfERC165(
+      deploy,
+      {
+        interfaceIds: ['0x2a55205a'],
+      },
+      skips,
+    );
+
     describe('#royaltyInfo()', () => {
       describe('reverts if', () => {
         it('royalty exceeds maximum', async function () {