Clean up tables in runner docs

What does this MR do?

As mentioned in gitlab-com/localization/docs-site-localization#49 (comment 2484218625), our localization service is currently struggling with tables that use single hyphens in the header separator, like:

| column | column |
|-|-|
| row | row |

Technically it's fine:

column	column
row	row

We'll try to fix the translation tooling, but we can still auto-format all the tables that use |-|-| which should fix the issue for now.

Related issues

• Related to gitlab-com/localization/docs-site-localization#49
• Related to Docs: Standardize and clean up table formatting (gitlab#545096 - closed)

Author's checklist

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Reviewer's checklist

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