GLAMOUR_STYLE env variable not respected

[tony-sol]

Describe the bug
GLAMOUR_STYLE env variable is not respected in glow renderer

Setup
Please complete the following information along with version numbers, if applicable.

• OS: macOS
• Shell: zsh
• Terminal Emulator: wezterm
• Terminal Multiplexer: tmux
• Locale: en_US.UTF-8

To Reproduce
Steps to reproduce the behavior:

1. remove style from config file
2. unset GLAMOUR_STYLE from env
3. run glow on any md file or run TUI - see 'auto' style
4. export GLAMOUR_STYLE=tokyo-night
5. run glow on any md file or run TUI - see 'auto' style not changed
6. add `style: tokyo-night" info config file
7. run glow on any md file or run TUI - see how style was changed
8. export GLAMOUR_STYLE=dark
9. run glow on any md file - see 'tokyo-night' style not changed

Source Code
no need

Expected behavior
Respect GLAMOUR_STYLE env variable in TUI mode (as code says) and in CLI mode

Screenshots

Additional context
none