internal/goversion: update Version to 1.19
This is the start of the Go 1.19 development cycle, so update the
Version value accordingly. It represents the Go 1.x version that will
soon open up for development (and eventually become released).
Updates #40705
Updates #51336
Change-Id: Ic4b3f2c04b1fa5c588cb6d62e829f2ed1864e511
Reviewed-on: https://go-review.googlesource.com/c/go/+/388376
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Trust: Alex Rakoczy <alex@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Alex Rakoczy <alex@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>