vim: Import v9.1.2125

* runtime(vim): Update base syntax, match Vim9 :unlet command
* runtime(doc): Improve the description at :help :cwindow

Author: github-actions[bot]

gitlog.txt

@@ -1 +1 @@
-* [9.1.2125](https://github.com/vim/vim/commit/b39b065d6fde5f214feebab882b8ebba78945035): MS-Windows: DirectX rendering can be improved\n* [runtime(qf): Update quickfix syntax](https://github.com/vim/vim/commit/01956225bc6f025d44419ddcad8176a3b12b3d7b)\n* [runtime(doc): Fix some overlength lines](https://github.com/vim/vim/commit/dd9f7e6cbbba6d8e63cca3b4c537dc9b8cc1837a)\n* [runtime(colors): improve catppuccin colorscheme](https://github.com/vim/vim/commit/c99aaf4c87771121f22ca6f196698ff707272810)\n* [9.1.2124](https://github.com/vim/vim/commit/2b184d4b97c370179a33aeb832cd77e737bbc480): blob2str() does not handle UTF-16 encoding\n* [9.1.2123](https://github.com/vim/vim/commit/ecc3faef61cb02f28028f27184ccd2aadcee7c24): using NOT with a float returns a float in legacy script\n* [9.1.2122](https://github.com/vim/vim/commit/3a5e57fc7eeaf67175223abc2bf7752891297721): Vim9: Negating a float doesn't result in a bool\n* [9.1.2121](https://github.com/vim/vim/commit/f5466b5a73686e55445600a06adbf6363c474a2b): Vim9: type issue when modifying a variable using :legacy\n* [9.1.2120](https://github.com/vim/vim/commit/611d7e19f7226d0b6b6be90e7623820feb9a0ca0): blob2str() does not restore trailing newline\n* [runtime(doc): Reformat example at :h gui-w32-fullscreen](https://github.com/vim/vim/commit/602e6042a3ee1c1d8caaf62e7d07cf74a504a809)
+* [runtime(vim): Update base syntax, match Vim9 :unlet command](https://github.com/vim/vim/commit/2e4c98b6f3db7d8e43645ccdf0b293cb07507ee1)\n* [runtime(doc): Improve the description at :help :cwindow](https://github.com/vim/vim/commit/079700ee45a0b838321ad1b15d13c36049d2a273)