When dns.query.https() is passed a source address, it needs to create an
adapter for either requests or httpx to use it.  As it doesn't know
which one will actually be used, it creates both.  But then if it
decides to use httpx, it attempts to attach the requests adapter, which
fails.

If both source and verify are passed to dns.query.https() when using
httpx, the verify parameter is ignored.  This is because the code
creates a custom transport for the source address, and httpx only uses the
verify parameter when creating a transport.

The fix is to pass in the verify parameter when we create a transport.