[DOCs] Remove extra { from Lazy.nvim package manager directions

[victorpre]

Description

Remove extra { which was included in the snippet merged on #2377

Fixes # (issue)

Type of change

• This change is a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list relevant details about your configuration

• Test A
• Test B

Configuration:

• Neovim version (nvim --version): v0.8.3
• Operating system and version: macOS Ventura 13.2

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)

[tjdevries]

Thanks!