Correct typing in the indexServerSide test

[ktipton]

Description

Correct the typing errors in the indexServerSide test. Due to the interaction between NextJS & Jest the typing is reporting issues, and due to how the context object is updated via the call, we cannot cast it to unknown.

Discovered & spun out of #571

$ yarn typecheck
$ tsc -p .
tests/pages/indexServerSide.test.ts:30:11 - error TS2322: Type 'GetServerSidePropsResult<{ [key: string]: any; }>' is not assignable to type 'GetServerSideProps<{ [key: string]: any; }, ParsedUrlQuery>'.
  Type '{ redirect: Redirect; }' is not assignable to type 'GetServerSideProps<{ [key: string]: any; }, ParsedUrlQuery>'.
    Type '{ redirect: Redirect; }' provides no match for the signature '(context: GetServerSidePropsContext<ParsedUrlQuery>): Promise<GetServerSidePropsResult<{ [key: string]: any; }>>'.

30     const result: GetServerSideProps = await getServerSideProps(context as GetServerSidePropsContext)
             ~~~~~~

tests/pages/indexServerSide.test.ts:30:65 - error TS2352: Conversion of type '{ req: { headers: {}; }; res: { statusCode: null; }; }' to type 'GetServerSidePropsContext<ParsedUrlQuery>' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
  Type '{ req: { headers: {}; }; res: { statusCode: null; }; }' is missing the following properties from type 'GetServerSidePropsContext<ParsedUrlQuery>': query, resolvedUrl

30     const result: GetServerSideProps = await getServerSideProps(context as GetServerSidePropsContext)
                                                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tests/pages/indexServerSide.test.ts:31:37 - error TS2339: Property 'props' does not exist on type 'GetServerSideProps<{ [key: string]: any; }, ParsedUrlQuery>'.

31     const props: HomeProps = result.props as HomeProps
                                       ~~~~~


Found 3 errors.

Acceptance Criteria

• All typing in indexServerSide test is corrected
• Remove //@ts-ignores & corresponding @typescript-eslint/ban-ts-comment comments from indexServerSide test
• Tests continue to function
• App continues to function