Changes

TiCDC: Increase memory limits for TiCDC Pulsar integration tests to improve stability (#4097)

# Increase Memory Limits for TiCDC Pulsar Integration Tests

This pull request increases the memory limits for two TiCDC Pulsar
integration test pipelines to improve stability and prevent potential
out-of-memory (OOM) failures during test execution.

## Changes Made

* Increased memory limit from `16Gi` to `24Gi` for the test container in
the `pull_cdc_pulsar_integration_light` pipeline.
* Increased memory limit from `16Gi` to `24Gi` for the test container in
the `pull_cdc_pulsar_integration_light_next_gen` pipeline.

## Why This Change is Necessary

Recent test runs have shown that the Pulsar integration tests, which
involve complex data streaming scenarios, can sometimes exceed the
previous 16Gi memory allocation under heavy load. This increase ensures
that the tests have sufficient headroom to run reliably without being
terminated due to memory constraints, leading to more consistent and
accurate test results.

Signed-off-by: tenfyzhong <tenfy@tenfy.cn>
 (commit: e3be600)