[release-branch.go1.22] cmd/go/internal/generate: call modload.InitWorkFile
This is necessary for go generate to enter workspace mode for
recognizing package paths in the workspace.
For #56098
Fixes #65352
Change-Id: I25f68de24f4189259353f63194823516e9d3d505
Reviewed-on: https://go-review.googlesource.com/c/go/+/559195
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
(cherry picked from commit
b91bad78199aaf8baeb66cb8a30f51b89b8f90ee)
Reviewed-on: https://go-review.googlesource.com/c/go/+/559236