fix ts for datatable

[britt6612]

What does this PR do?

Update the TS def for rowDetails in DataTable

Where should the reviewer start?

index.d.ts

What testing has been done on this PR?

locally

How should this be manually tested?

Do Jest tests follow these best practices?

• screen is used for querying.
• The correct query is used. (Refer to this list of queries)
• userEvent is used in place of fireEvent.
• asFragment() is used for snapshot testing.

Any background context you want to provide?

rowDetails takes a function as its argument. For example:

rowDetails={(row) => {return I am a box;}}

Typescript throws this error:

TS2769: No overload matches this call.
Overload 1 of 2, '(props: DataTableExtendedProps | Readonly<DataTableExtendedProps>): DataTable<...>', gave the following error.
Type '() => JSX.Element' is not assignable to type 'ReactNode'.
Overload 2 of 2, '(props: DataTableExtendedProps, context: any): DataTable', gave the following error.
Type '() => JSX.Element' is not assignable to type 'ReactNode'.

To fix it, I have updated src/js/components/DataTable/index.d.ts

I replace line 86 with this:

rowDetails?: (row: TRowType) => React.ReactNode;

What are the relevant issues?

closes #6477

Screenshots (if appropriate)

Do the grommet docs need to be updated?

no

Should this PR be mentioned in the release notes?

no

Is this change backwards compatible or is it a breaking change?

backwards compatible

[jcfilben]

Looks good!