find/glob: Don't use `$.` as a non-matching regex

[tavianator]

The oniguruma version built by onig_sys does not include the commit 6f7b0aa ("add ONIG_SYN_BRE_ANCHOR_AT_EDGE_OF_SUBEXP into ONIG_SYNTAX_POSIX_BASIC and ONIG_SYNTAX_GREP"), causing $. to actually match a literal newline.

Using $. is not portable anyway; POSIX says

A <dollar-sign> ( '$' ) shall be an anchor when used as the last character of an entire BRE.

[github-actions[bot]]

Commit 4be8be2f5217a9aacc8983d0b374c485871c7f75 has GNU testsuite comparison:

Run GNU findutils tests: GNU tests summary = TOTAL: 651 / PASS: 481 / FAIL: 167 / ERROR: 2
Run GNU findutils tests: Changes from main: PASS +0 / FAIL +0 / ERROR +0 / SKIP +0 
Run GNU findutils tests: Gnu tests No changes
Run BFS tests: Congrats! The bfs test posix/name_backslash is now passing!
Run BFS tests: Changes from main: PASS +1 / SKIP +0 / FAIL -1
Run BFS tests: BFS tests summary = TOTAL: 317 / PASS: 247 / SKIP: 6 / FAIL: 64

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 77.29%. Comparing base (b641b85) to head (e8fdd68). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #457 +/- ## ======================================= Coverage 77.29% 77.29% ======================================= Files 36 36 Lines 4436 4436 Branches 991 991 ======================================= Hits 3429 3429 Misses 1004 1004 Partials 3 3 ```

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[github-actions[bot]]

Commit e8fdd689f29d5f741ae300e567c37e8ebe30e30f has GNU testsuite comparison:

Run GNU findutils tests: GNU tests summary = TOTAL: 651 / PASS: 481 / FAIL: 167 / ERROR: 2
Run GNU findutils tests: Changes from main: PASS +0 / FAIL +0 / ERROR +0 / SKIP +0 
Run GNU findutils tests: Gnu tests No changes
Run BFS tests: Congrats! The bfs test posix/name_backslash is now passing!
Run BFS tests: Changes from main: PASS +1 / SKIP +0 / FAIL -1
Run BFS tests: BFS tests summary = TOTAL: 317 / PASS: 247 / SKIP: 6 / FAIL: 64