ANSI-coloured header from from preview doesn't render correctly in Powershell 7

[TheRealGLH]

Describe the bug
I've set the header to load from a text file with ANSI escape sequences for the colors, but it seems to get corrupted when opening Neovim in Powershell 7. Powershell 7 can actually render the file correctly with cat, even in the Neovim terminal itself; the corrupted look only happens in the header and only in Powershell.
I've tested this same config both with WSL Ubuntu (in the same Windows Terminal app) and in ZSH in iTerm2 where it seems to work as expected.
To Reproduce
Steps to reproduce the behavior:

1. Run Neovim with the linked config in Powershell 7
2. Notice the splash art is corrupted
3. Open the Neovim terminal
4. cat the dashboard-ansi.txt file in the root of the repository
5. Notice how it renders perfectly fine in Powershell, even inside of Neovim

Expected behavior
I expected it to render exactly as it does with the cat command, the way it also does in ZSH and WSL Bash.

Screenshots

Incorrect rendering in Neovim header w/ Powershell 7

Correct rendering in Neovim header w/ WSL Ubuntu

Correct rendering in Powershell 7 w/ cat command