This adds support for identifying which worker is running a test file
when tests execute concurrently, similar to JEST_WORKER_ID in Jest,
VITEST_POOL_ID in Vitest, and MOCHA_WORKER_ID in Mocha.

When running with --test-isolation=process (default), each test file
runs in a separate child process and receives a unique worker ID from
1 to N. When running with --test-isolation=none, all tests run in the
same process and the worker ID is always 1.

This enables users to allocate separate resources (databases, ports,
etc.) for each test worker to avoid conflicts during concurrent
execution.

Changes:
- Add WorkerIdPool class to manage worker ID allocation and reuse
- Set NODE_TEST_WORKER_ID environment variable for child processes
- Add context.workerId getter to TestContext class
- Add tests for worker ID functionality
- Add documentation for context.workerId

Fixes: #55842
PR-URL: #61394
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Pietro Marchini <[email protected]>
Reviewed-By: Jacob Smith <[email protected]>

Notable changes:

build, doc:
  * use new api doc tooling (flakey5) #57343
sqlite:
  * (SEMVER-MINOR) add limits property to DatabaseSync (Mert Can Altin) #61298
src:
  * (SEMVER-MINOR) add C++ support for diagnostics channels (RafaelGSS) #61869
src,permission:
  * (SEMVER-MINOR) add --permission-audit (RafaelGSS) #61869
test_runner:
  * (SEMVER-MINOR) expose worker ID for concurrent test execution (Ali Hassan) #61394

PR-URL: #62073

Notable changes:

build, doc:
  * use new api doc tooling (flakey5) #57343
sqlite:
  * (SEMVER-MINOR) add limits property to DatabaseSync (Mert Can Altin) #61298
src:
  * (SEMVER-MINOR) add C++ support for diagnostics channels (RafaelGSS) #61869
src,permission:
  * (SEMVER-MINOR) add --permission-audit (RafaelGSS) #61869
test_runner:
  * (SEMVER-MINOR) expose worker ID for concurrent test execution (Ali Hassan) #61394

PR-URL: #62073