Use ONIG_OPTION_FIND_NOT_EMPTY for None-operation match patterns to fix syntest failures

[Copilot]

• Add allow_empty: bool parameter to Regex::search() and implement FIND_NOT_EMPTY support for None-operation patterns
• Update public API snapshot (tests/snapshots/public-api.txt) to reflect new search() signature
• Run cargo fmt to fix formatting issues in regex.rs and yaml_load.rs
• Update testdata/known_syntest_failures.txt (Oniguruma) — all 3 failures (C#, LaTeX, Makefile) expected to be resolved
• Update testdata/known_syntest_failures_fancy.txt (fancy-regex) — C# and LaTeX failures expected resolved; Markdown remains

[keith-hall]

Looks like we need to update the documented public api in order to get tests to pass on CI @copilot. Also if we did fix the syntest assertion failures, we will need to update the known failures file too, please see the github actions workflow to see what commands to run to check with

[Copilot]

Looks like we need to update the documented public api in order to get tests to pass on CI @copilot. Also if we did fix the syntest assertion failures, we will need to update the known failures file t...

Fixed in 95ac654:

• Updated tests/snapshots/public-api.txt to reflect the new search(&self, ..., allow_empty: bool) signature
• Ran cargo fmt to fix formatting issues in regex.rs and yaml_load.rs
• Updated testdata/known_syntest_failures.txt (Oniguruma) — all 3 failures (C#, LaTeX, Makefile) should now be resolved by the FIND_NOT_EMPTY fix
• Updated testdata/known_syntest_failures_fancy.txt — C# and LaTeX expected resolved; Markdown (not caused by empty matches on None patterns) remains