[7.x] Bump highlight.js to v9.18.5 (#84296)

[jportner]

Backports the following commits to 7.x:

• Bump highlight.js to v9.18.5 (Bump highlight.js to v9.18.5 #84296)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 5073ba6

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
apm	1153	1720	+567

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
apm	3.1MB	5.4MB	⚠️ +2.3MB
enterpriseSearch	1.3MB	1.3MB	+97.0B
total			⚠️ +2.3MB

Distributable file count

id	before	after	diff
default	47289	48063	+774

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
apm	48.8KB	48.8KB	+8.0B
upgradeAssistant	60.3KB	60.4KB	+97.0B
total			+105.0B

Unknown metric groups

@kbn/ui-shared-deps asset size

id	before	after	diff
kbn-ui-shared-deps.@elastic.js	3.2MB	2.4MB	-765.1KB
kbn-ui-shared-deps.js	14.0MB	14.8MB	⚠️ +812.9KB
total			+47.8KB

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream