Update micromamba-installation.rst

[KasperThystrup]

Description

In installation instructions for Ubuntu
Changed curl to wget for ubuntu instalation since Curl is not installed by default. Currently it's two commands in a one-liner.

Type of Change

• Bugfix
• Feature / enhancement
• [X ] CI / Documentation
• Maintenance

Checklist

• [X ] My code follows the general style and conventions of the codebase, ensuring consistency
• [ X] I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• [ X] My changes generate no new warnings
• I have run pre-commit run --all locally in the source folder and confirmed that there are no linter errors.
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes

[Klaim]

I would prefer if you also kept the curl version and just add the wget command as an alternative.

Also note that there are mentions on the curl line 43 and 49, so keeping it would keel the rest of the documentation in sync.