Fix DOM nesting issues reported by validateDOMNesting

[tkajtoch]

Running React 18 and RTL tests reported a small amount of DOM nesting errors that should be fixed.

@tkajtoch to list all errors when RTL test conversion PRs are merged (#6968, #6969, #6970, #6971, #6972, #6973, #6974, #6975, #6976, #6977).

[JasonStoltz]

Per Tomasz, this may be affecting SSR code as well. EUIText is the primary component this is affecting.

[JasonStoltz]

@tkajtoch Can you put a list of non-production affecting components to fix in the short-term?

[breehall]

Running list of component throwing validateDOMNesting warnings:

• EuiTableHeaderCellCheckbox
• EuiRowCell
• EuiHeaderCell
• EuiTableRowCellCheckbox
• EuiTableFooter
• EuiTableRow
• EuiTableHeader