ci: four shards for webkit specs.

Author: knightedcodemonkey

.github/workflows/playwright.yml

@@ -39,20 +39,25 @@ jobs:
             shardIndex: 1
             shardTotal: 1
           - browser: webkit
-            jobName: E2E (Playwright, webkit, shard 1/3)
+            jobName: E2E (Playwright, webkit, shard 1/4)
             workers: 1
             shardIndex: 1
-            shardTotal: 3
+            shardTotal: 4
           - browser: webkit
-            jobName: E2E (Playwright, webkit, shard 2/3)
+            jobName: E2E (Playwright, webkit, shard 2/4)
             workers: 1
             shardIndex: 2
-            shardTotal: 3
+            shardTotal: 4
           - browser: webkit
-            jobName: E2E (Playwright, webkit, shard 3/3)
+            jobName: E2E (Playwright, webkit, shard 3/4)
             workers: 1
             shardIndex: 3
-            shardTotal: 3
+            shardTotal: 4
+          - browser: webkit
+            jobName: E2E (Playwright, webkit, shard 4/4)
+            workers: 1
+            shardIndex: 4
+            shardTotal: 4
 
     steps:
       - name: Checkout