tests(core/seo): fix racy tests (speced#3999)

tests/spec/core/seo-spec.js

@@ -16,15 +16,8 @@ describe("Core — Seo", () => {
       body: makeDefaultBody(),
     };
     const doc = await makeRSDoc(ops);
-    await doc.respec.ready;
-    await new Promise(resolve => {
-      const check = () => {
-        const hasMetaDesc = doc.querySelectorAll("meta[name=description]");
-        expect(hasMetaDesc).toHaveSize(0);
-        resolve();
-      };
-      window.requestIdleCallback ? window.requestIdleCallback(check) : check();
-    });
+    const hasMetaDesc = doc.querySelectorAll("meta[name=description]");
+    expect(hasMetaDesc).toHaveSize(0);
   });
 
   it("inserts a meta element for the description after processing", async () => {
@@ -37,25 +30,9 @@ describe("Core — Seo", () => {
       body: makeDefaultBody(),
     };
     const doc = await makeRSDoc(ops);
-    await doc.respec.ready;
-    await new Promise(resolve => {
-      const check = () => {
-        const hasMetaDesc = doc.querySelectorAll(
-          "meta[name=description]"
-        ).length;
-        // Firefox is buggy, short circuit
-        if (navigator.userAgent.includes("Firefox") && !hasMetaDesc) {
-          expect(true).toBe(true);
-          return;
-        }
-        expect(hasMetaDesc).toBe(1);
-        const meta = doc.head.querySelector("meta[name=description]");
-        expect(meta.content).toBe("Pass");
-        resolve();
-      };
-      window.requestIdleCallback
-        ? doc.defaultView.requestIdleCallback(check)
-        : check();
-    });
+    const hasMetaDesc = doc.querySelectorAll("meta[name=description]").length;
+    expect(hasMetaDesc).toBe(1);
+    const meta = doc.head.querySelector("meta[name=description]");
+    expect(meta.content).toBe("Pass");
   });
 });