Fixes bug [53826](https://bugs.winehq.org/show_bug.cgi?id=53826).
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v20: ntdll/tests: Increase margins in timer merging tests.
ntdll: Set xattr in NtCreateFile if inferred and requested attributes don't match.
ntdll: Only infer hidden attribute from file name if xattr is not present.
ntdll: Handle hidden file names inside get_file_info instead of after it.
ntdll: Do not open-code hidden file handling in get_dir_data_entry.
ntdll/tests: Add test for file attributes of files with names beginning with a dot.
https://gitlab.winehq.org/wine/wine/-/merge_requests/1148