Bug: vim.tbl_flatten is deprecated in latest Neovim

[hood]

Describe the bug
As Neovim reports upon loading the plugin:

vim.tbl_flatten is deprecated, use vim.iter(…):flatten():totable() instead.

To Reproduce
Use the plugin in versions of Neovim after commit 2088521263d3bf9cfd23729adb1a7d152eaab104.

Expected behavior
The plugin should use non-deprecated vim functions.

Screenshots

Operating System:

Neovim Version:
0.10

Colorizer Version:
a065833f35a3a7cc3ef137ac88b5381da2ba302e

Additional context