Changes

ci(replay): ignore deleted groovy files in auto-changed mode (#4280)

## Summary
- fix `.ci/replay-jenkins-build.sh` auto-changed discovery to exclude
deleted files
- prevent replay presubmit from failing when a pipeline groovy is
intentionally removed in a PR

## Root cause
In `pull-replay-jenkins-pipelines`, the script collected changed files
with `git diff --name-only`, which included deleted paths. Replay then
aborted on:

`ERROR: script file not found:
pipelines/tikv/pd/latest/pull_unit_test.groovy`

## Verification
- reproduced from `pull-replay-jenkins-pipelines` log on PR #4266
- local dry-run with the same base/head range now excludes deleted files
and completes

Ref #4213

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: wuhuizuo <2574558+wuhuizuo@users.noreply.github.com>
 (commit: dba7dbc)