test(codemode): drop the slow split and matchAll cap cases (#49051)

packages/codemode/test/limits.test.ts

@@ -39,14 +39,14 @@ describe("one built-in cannot build an unbounded value", () => {
     }
   })
 
-  test("arrays: constructor, length, Array.from, split, matchAll, concat, flat", async () => {
+  // split and matchAll share the same result check but must build ten million items first to reach it,
+  // which is too slow for CI.
+  test("arrays: constructor, length, Array.from, concat, flat", async () => {
     expect(await value(`return Array(${A}).length`)).toBe(A)
     for (const code of [
       `Array(${A + 1})`,
       `const a = []; a.length = ${A + 1}`,
       `Array.from({ length: ${A + 1} })`,
-      `"x".repeat(${S}).split("")`,
-      `"x".repeat(${A + 1}).matchAll(/x/g)`,
       `Array(${A}).concat([1])`,
       `[Array(${A}).fill(0), [1]].flat()`,
     ]) {