cmd/go/internal/toolchain: revert "make a best effort to parse 'go run' and 'go insta...

cmd/go/internal/toolchain: revert "make a best effort to parse 'go run' and 'go install' flags"

This caused other problems, and for the purposes of the Go 1.22
release, we can just roll back to the Go 1.21 behavior and then
decide in January what the correct path forward is.

Revert of CL 546635.

Unfixes #64282.
Fixes #64738.
For #57001.

This reverts commit e44b8b15b19058b7a22a859ab4159f924856f688.

Change-Id: I78753c76dcd0bc6dbc90caa17f73248c42e5f64a
Reviewed-on: https://go-review.googlesource.com/c/go/+/551215
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Than McIntosh <thanm@google.com>