Fix CSPELL issues

Problem/Motivation

Fix CSPELL issues in pipeline

CSpell: Files checked: 8, Issues found: 1 in 1 file.
The number of unrecognised/misspelled words is 1
An artifact file has been created containing a list of these unrecognized words, for you to browse or download.
For hints on getting this CSPELL job to pass see https://project.pages.drupalcode.org/gitlab_templates/jobs/cspell/
=== This is _cspell_unrecognized_words.txt ===
Hoverable

This says Hoverable is not a recognized word.

Steps to reproduce

See https://git.drupalcode.org/project/bootstrap_utilities/-/jobs/2402388
See https://git.drupalcode.org/project/bootstrap_utilities/-/blob/3.0.x/src/...

Proposed resolution

In the context of this module I think we should add Hoverable to the list of ignored words because this is Bootstrap terminology.
https://getbootstrap.com/docs/5.3/content/tables/#hoverable-rows

Add _CSPELL_WORDS: 'Hoverable' to the gitlab ci file.

################
# Pipeline configuration variables
#
# These are the variables provided to the Run Pipeline form that a user may want to override.
#
# Docs at https://git.drupalcode.org/project/gitlab_templates/-/blob/main/includes/include.drupalci.variables.yml
################
variables:
  _CSPELL_WORDS: 'Hoverable'

Remaining tasks

N/A

User interface changes

N/A

API changes

N/A

Data model changes

N/A