LabeledSelect: Show tag prompts only if select is searchable

[houhoucoop]

Summary

Fixes #6946

when there were no options, the prompt text start typing to delete an item would appear even if the select was not searchable.

Occurred changes and/or fixed issues

• Modified the logic to ensure the prompt only shows if the select is searchable

Technical notes summary

The showTagPrompts was introduced in PR#12350
Ref: https://github.com/rancher/dashboard/pull/12350/files#diff-5316c4da698262a356a5f70f02f4d94b95c66b780cedf9cb04515deb011017d8R148-R151

Areas or cases that should be tested

Verify the prompt text only appears when:

• There are no options available and select is both taggable and searchable

Areas which could experience regressions

Prompt display behavior in LabeledSelect component when there are no options

Screenshot/Video

Show No options if the select was not searchable

Checklist

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[torchiaf]

LGTM since the new prop was introduced in 2.10.1 I don't expect that the new condition would break anything in Rancher