git: add less.exe bin

`less` is relied upon by popular diff viewers such as [delta] or
[diff-so-fancy], so including it makes sense. Furthermore, less v551
bundled with Git fixes issues in older versions. For instance, v394
bundled with Gow has [problems with UTF-8] and [an update seems
unlikely], sadly.

[delta]: https://github.com/dandavison/delta
[diff-so-fancy]: https://github.com/so-fancy/diff-so-fancy
[problems with UTF-8]: dandavison/delta#271
[an update seems unlikely]: bmatzelle/gow#250

bucket/git.json

@@ -17,6 +17,7 @@
         "cmd\\git.exe",
         "cmd\\gitk.exe",
         "cmd\\git-gui.exe",
+        "usr\\bin\\less.exe",
         "usr\\bin\\tig.exe",
         "git-bash.exe"
     ],