Keep log assertions small

The longer the list of log lines asserted one, the harder future diffs are to comprehend.
git-diff produces hard to decipher diffs if the StrictEffects behavior is changed slightly that results in more lines added.
It won't be obvious anymore which lines were added and which ones were removed.

packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js

@@ -900,8 +900,17 @@ describe('StrictEffectsMode', () => {
       );
     });
 
+    expect(log).toEqual([
+      'Parent rendered',
+      'Parent rendered',
+      'Child rendered',
+      'Child suspended',
+      'Fallback',
+      'Fallback',
+    ]);
+
+    log = [];
     // while suspended, update
-    log.push('-----------------------after update');
     await act(() => {
       ReactNoop.render(
         <React.StrictMode>
@@ -910,32 +919,26 @@ describe('StrictEffectsMode', () => {
       );
     });
 
-    // Now resolve and commit
-    log.push('-----------------------after suspense');
+    expect(log).toEqual([
+      'Parent rendered',
+      'Parent rendered',
+      'Child rendered',
+      'Child suspended',
+      'Fallback',
+      'Fallback',
+      'Parent dep destroy',
+      'Parent dep create',
+    ]);
 
+    log = [];
+    // Now resolve and commit
     await act(() => {
       resolve();
       shouldSuspend = false;
     });
 
     if (gate(flags => flags.useModernStrictMode)) {
       expect(log).toEqual([
-        'Parent rendered',
-        'Parent rendered',
-        'Child rendered',
-        'Child suspended',
-        'Fallback',
-        'Fallback',
-        '-----------------------after update',
-        'Parent rendered',
-        'Parent rendered',
-        'Child rendered',
-        'Child suspended',
-        'Fallback',
-        'Fallback',
-        'Parent dep destroy',
-        'Parent dep create',
-        '-----------------------after suspense',
         'Child rendered',
         'Child rendered',
         // !!! Committed, destroy and create effect.
@@ -957,22 +960,6 @@ describe('StrictEffectsMode', () => {
       ]);
     } else {
       expect(log).toEqual([
-        'Parent rendered',
-        'Parent rendered',
-        'Child rendered',
-        'Child suspended',
-        'Fallback',
-        'Fallback',
-        '-----------------------after update',
-        'Parent rendered',
-        'Parent rendered',
-        'Child rendered',
-        'Child suspended',
-        'Fallback',
-        'Fallback',
-        'Parent dep destroy',
-        'Parent dep create',
-        '-----------------------after suspense',
         'Child rendered',
         'Child rendered',
         'Child dep destroy',