Fix the glob pattern of excludeNonCssFiles

[precondition]

~/Coding/vredeburg/src/assets/css
❯ tree
.
├── custom-forms.css
├── main.css
├── nouislider.min.css
├── something.txt
└── testdir
    └── nested.css

1 directory, 5 files

~/Coding/vredeburg/src/assets/css
❯ node
Welcome to Node.js v16.6.1.
Type ".help" for more information.
> const fg = require("fast-glob")
undefined
> await fg("**", {"ignore": ['**/!(*.css)']})
[]
> await fg("**", {"ignore": ['!(**.css)']})
[
  'custom-forms.css',
  'main.css',
  'nouislider.min.css',
  'testdir/nested.css'
]
> 

As you can see, using '**/!(*.css)' excludes everything from the results.

[precondition]

bump