Git: exclude commits by an author in git log with --perl-regexp

git log supports an --author flag to filter commits by author, but lacks a built-in way to exclude authors. Using --perl-regexp, you can embed a negative lookahead regex (^((?!<pattern>).)*$) into the --author option to show all commits except those from a matching author. A practical example demonstrates filtering out Dependabot bot commits when browsing GitHub Actions workflow history. Note that --perl-regexp requires Git to be compiled with PCRE support.