Apparently the `cobertura-merge` dependency had some transitive
dependencies (`nan` and `node-expat`) which compiled some C extensions
for node. The dependency was introduced in:
gitlab-org/gitlab-ui!4301

The problem ensued because some of the playwright  and cypress images
shipped slightly different node versions than what we are caching
dependencies with. Subsequently we added two C compilers:
- gitlab-org/gitlab-ui!4452
- gitlab-org/gitlab-ui!4520

Seems like we are not the only ones hitting the problem and someone
created `merge-cobertura`: https://www.npmjs.com/package/merge-cobertura
which doesn't rely on XML parsers with native extensions. This one is
likely a little slower. But given that this runs in CI, probably not a
big problem.

SCSS variable switches between different button styles.
Users will see old buttons until a project set
$feature-button-border SCSS variable to true.

Mirgate animation properties to variables.
Support @prefers-reduced-motion.
Migrate box-shadow to borders for buttons
in  GlButton, GlDisclosureDropdown, GlFilteredSearch,
GlSegmentedControl and GlSearchboxByClick components.

chore: Get rid of not one but two C compilers

See merge request gitlab-org/gitlab-ui!4657



Merged-by: Mark Florian <mflorian@gitlab.com>
Approved-by: Mark Florian <mflorian@gitlab.com>
Co-authored-by: Lukas Eipert <leipert@gitlab.com>

feat(GlButton): Add animation and migrate box-shadow to border

See merge request gitlab-org/gitlab-ui!4506



Merged-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Approved-by: Scott de Jonge <sdejonge@gitlab.com>
Approved-by: Dan MH <dmizzi-harris@gitlab.com>
Reviewed-by: Paul Slaughter <pslaughter@gitlab.com>
Reviewed-by: Scott de Jonge <sdejonge@gitlab.com>
Co-authored-by: GitLab Bot <gitlab-bot@gitlab.com>
Co-authored-by: Julia Miocene <jmiocene@gitlab.com>

# [94.9.0](gitlab-org/gitlab-ui@v94.8.0...v94.9.0) (2024-10-03)

### Features

* **GlButton:** Add animation and migrate box-shadow to border ([602811dc](gitlab-org/gitlab-ui@602811dc))