fix + reformat linux/macos collector commands

[SylvainJuge]

The lack of && at the end of variables setting makes them ignored in the following sed (at least in my local setup).

we can simplify a bit and remove the rm command as the file is overwriten with the cp command, also we can simplify escaping by making the sed expression interpolated rather than concatenated.

With those changes, the only difference between the macos and linux is the extra '' argument in the inline sed invocation.

[elastic-acrolinx]

Acrolinx Scorecards

Select the total score link to review all feedback on clarity, consistency, tone, brand, terms, spelling, grammar, readability, and inclusive language. You should fix all spelling errors regardless of your total score. Fixing spelling errors helps maintain user trust in overall content quality.

Article	Total score (Required: 80)	Words + phrases (Brand, terms)	Correctness (Spelling, grammar)	Clarity (Readability)
✅ docs/quickstart/self-managed/hosts_vms.md	64	26	38	42

*TBD

[elastic-acrolinx]

Acrolinx Scorecards

Select the total score link to review all feedback on clarity, consistency, tone, brand, terms, spelling, grammar, readability, and inclusive language. You should fix all spelling errors regardless of your total score. Fixing spelling errors helps maintain user trust in overall content quality.

Article	Total score (Required: 80)	Words + phrases (Brand, terms)	Correctness (Spelling, grammar)	Clarity (Readability)
✅ docs/quickstart/self-managed/hosts_vms.md	64	26	38	42

*TBD