chore: don't panic if clipboard cannot be accessed

[dhth]

Fixes #1707.

Summary

atuin doesn't panic if the system clipboard cannot be accessed for any reason.

Questions

• Do we also want to stop panicking if setting text to the clipboard fails?
• Do we also want to stop panicking if the follow up check to see if the value was set fails?
• Should we add an error message to the TUI if any of the steps involved fail?

Checks

• I am happy for maintainers to push small adjustments to this PR, to speed up the review cycle
• I have checked that there are no existing pull requests for the same thing