Try to skip Multichain tests using jest

  - Previous solution assumed we used Mocha, but we're using Jest

packages/payment-detection/test/eth/info-retriever.test.ts

@@ -45,14 +45,11 @@ describe('api/eth/info-retriever', () => {
     await expect(infoRetreiver.getTransferEvents()).rejects.toThrowError();
   });
 
-  describe('Multichain', function (this: Mocha.Context) {
-    // Skip tests if build is from external fork or API tests are disabled
-    // External forks cannot access secrets API keys
-    if (process.env.CIRCLE_PR_NUMBER || process.env.DISABLE_API_TESTS) {
-      console.warn('Skipping API tests');
-      this.skip();
-    }
-
+  // Skip tests if build is from external fork or API tests are disabled
+  // External forks cannot access secrets API keys
+  const describeIf =
+    process.env.CIRCLE_PR_NUMBER || process.env.DISABLE_API_TESTS ? describe : describe.skip;
+  describeIf('Multichain', () => {
     // TODO temporary disable xDAI, CELO, Sokol, and Goerli
     // FIXME: API-based checks should run nightly and be mocked for CI
     [