Ensure dynamic routes dont match _next/static unexpectedly (#62559)
This ensures our dynamic routes that have the same specificity as
`_next/static/:path*` don't get matched unexpectedly when the
`_next/static` asset doesn't exist. We were holding off on making this
change explicit due to compatibility concerns but these are no longer a
concern and the unexpected matching is more of a concern.
Closes: CSM-11
Fixes: https://github.com/vercel/next.js/issues/19270
Closes NEXT-2613