fix: make heap snapshot OOM test allocate faster

[ckerr]

Description of Change

Fix a timeout CI flake in utilityProcess module behavior supports generating snapshots via v8.setHeapSnapshotNearHeapLimit:

1. The oom-grow.js fixture triggers OOM to test v8.setHeapSnapshotNearHeapLimit. At ~1KB/tick it needs ~50K iterations to fill 50MB, but V8 (43aa3906777, --late-heap-limit-check) now defers limit checks, so the process never OOMs within the 30s timeout. Fix by allocating 1MB/tick to reach OOM faster.

2. Change the 'max-old-space-size' from 50 MB to 20 MB to try to exhaust the memory pool faster.

3. Add '--no-late-heap-limit-check' to try to undo https://chromium-review.googlesource.com/c/v8/v8/+/6919127 which may be contributing to this flake.

Sample CI failure:

Failure in test: "utilityProcess module behavior supports generating snapshots via v8.setHeapSnapshotNearHeapLimit"
Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/1/b/src/electron/spec/api-utility-process-spec.ts)
    at createTimeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/errors.js:498:15)
    at Test.Runnable._timeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/runnable.js:429:10)
Retrying test (1/3)...
Failure in test: "utilityProcess module behavior supports generating snapshots via v8.setHeapSnapshotNearHeapLimit"
Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/1/b/src/electron/spec/api-utility-process-spec.ts)
    at createTimeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/errors.js:498:15)
    at Test.Runnable._timeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/runnable.js:429:10)
Retrying test (2/3)...
Failure in test: "utilityProcess module behavior supports generating snapshots via v8.setHeapSnapshotNearHeapLimit"
Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/1/b/src/electron/spec/api-utility-process-spec.ts)
    at createTimeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/errors.js:498:15)
    at Test.Runnable._timeoutError (/Users/runner/work/1/b/src/electron/spec/node_modules/mocha/lib/runnable.js:429:10)
Retrying test (3/3)...
not ok 222 utilityProcess module behavior supports generating snapshots via v8.setHeapSnapshotNearHeapLimit
  Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/1/b/src/electron/spec/api-utility-process-spec.ts)
  Error: Timeout of 30000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/Users/runner/work/1/b/src/electron/spec/api-utility-process-spec.ts)
      at listOnTimeout (node:internal/timers:605:17)
      at processTimers (node:internal/timers:541:7) 
[32290:0511/035302.871179:ERROR:base/process/kill_posix.cc:86] Unable to terminate process 41701: No such process (3)
[32290:0511/035302.871294:ERROR:base/process/kill_posix.cc:32] waitpid(41701): No child processes (10)
[32290:0511/035304.674475:ERROR:base/process/kill_posix.cc:86] Unable to terminate process 41877: No such process (3)
[32290:0511/035304.674540:ERROR:base/process/kill_posix.cc:32] waitpid(41877): No child processes (10)
ok 223 utilityProcess module behavior supports --no-experimental-global-navigator flag
[32290:0511/035305.973469:ERROR:base/process/kill_posix.cc:86] Unable to terminate process 41981: No such process (3)
[32290:0511/035305.973527:ERROR:base/process/kill_posix.cc:32] waitpid(41981): No child processes (10)

Checklist

• I have built and tested this change
• I have filled out the PR description
• I have reviewed and verified the changes
• npm test passes
• tests are changed or added

Release Notes

Notes: none.