Mk/Uses/go.mk: Revert part of 4e29133

Revert module cache revalidation in post-fetch (`go mod verify`), it
breaks non-root poudriere builds.

`go mod verify` needs read/write access to the GOMODCACHE and because
extract stage runs fetch stage again but under a restricted user, `go
mod verify` fails with a "permission denied" error.

Mk/Uses/go.mk

@@ -166,8 +166,7 @@ post-fetch:
 	@${ECHO_MSG} "===> Fetching ${GO_MODNAME} dependencies";
 	@(cd ${DISTDIR}/${DIST_SUBDIR}; \
 		[ -e go.mod ] || ${RLN} ${GO_MODFILE} go.mod; \
-		${SETENV} ${GO_ENV} GOPROXY=${GO_GOPROXY} ${GO_CMD} mod download -x; \
-		${SETENV} ${GO_ENV} GOPROXY=${GO_GOPROXY} ${GO_CMD} mod verify)
+		${SETENV} ${GO_ENV} GOPROXY=${GO_GOPROXY} ${GO_CMD} mod download -x)
 .  endif
 
 .  if !target(post-extract)