fix: invalid characters in label instance-type of robot servers

[lukasmetzner]

Invalid characters like ™ should be removed when generating the instance-type label for Robot servers.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 70.75%. Comparing base (e6c0356) to head (6e9fb48). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #770 +/- ## ========================================== + Coverage 70.73% 70.75% +0.01% ========================================== Files 31 31 Lines 3188 3190 +2 ========================================== + Hits 2255 2257 +2 Misses 760 760 Partials 173 173 ```

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[lukasmetzner]

Syntax and character set

The name segment is required and must be 63 characters or less, beginning and ending with an alphanumeric character ([a-z0-9A-Z]) with dashes (-), underscores (_), dots (.), and alphanumerics between.

There are some additional cases we do not cover yet like:

• 63 chars or less
• alphanumeric at beginning or end

Should we do something specific about them, e.g trim label, trim characters and beginning or end? @apricote

[apricote]

Looking at the list of previous models I do not think we run into any problems with length or non-alphanumeric characters for now: https://docs.hetzner.com/robot/dedicated-server/general-information/root-server-hardware#hardware-configuration