FURB167: change example to `re.search` with `^` anchor (#22984)
## Summary
The example for
[FURB167](https://docs.astral.sh/ruff/rules/regex-flag-alias/#regex-flag-alias-furb167)
has `re.match` with an `^` anchor to match the start of the string:
```python
if re.match("^hello", "hello world", re.I):
```
But `re.match` already implicitly matches the start of the string:
https://docs.python.org/3/library/re.html#search-vs-match
Let's change the example to `re.search` so the anchor isn't redundant.
(The anchor's actually irrelevant to the example for this rule about
long or short flag names.)
(Aside: There's a discussion about adding `re.prefixmatch` and [soft]
deprecating `re.match` because of the confusion around it:
https://discuss.python.org/t/add-re-prefixmatch-deprecate-re-match/105927,
https://github.com/python/cpython/issues/86519,
https://github.com/python/cpython/pull/31137.)
## Test Plan
<!-- How was it tested? -->
1. Create feature branch
2. Push to my fork to run CI
3. Realise feature branches are disabled for forks in Ruff CI
4. Merge feature branch to my `main`
5. Push that
6. Be happy I did, because it failed because I missed something
7. Fixup, pushup
8. Passes [🎉](https://github.com/hugovk/ruff/actions/runs/21524112749)
