[24.11] matomo: fix quoting in cleanup shell script

[osnyx]

Forward-port of #1279 to the correct intended branch. As it accidentally went to an earlier NixOS platform release branch earlier, we've reverted it in #1301.
The changes are designed for an environment where matomo-4 does not play a role anymore. This is the case in 24.11, but not yet in 24.05.

PL-133012

@flyingcircusio/release-managers

Release process

• Created changelog entry using ./changelog.sh

PR release workflow (internal)

• PR has internal ticket
• internal issue ID (PL-…) part of branch name
• internal issue ID mentioned in PR description text
• ticket is on Platform agile board
• ticket state set to Pull request ready
• if ticket is more urgent than within the next few days, directly contact a member of the Platform team

Design notes

• Provide a feature toggle if the change might need to be adjusted/reverted quickly depending on context. Consider whether the default should be on or off. Example: rate limiting.
• All customer-facing features and (NixOS) options need to be discoverable from documentation. Add or update relevant documentation such that hosted and guided customers can understand it as well.

Security implications

• Security requirements defined? (WHERE)
  • forwardport of an alread approved change
• Security requirements tested? (EVIDENCE)
  • automated tests still pass