cmd/go: remove references to gopath-get

Fixes #70912

Change-Id: Id87a13f7c9bf972502d14c9674a27f743b849715
Reviewed-on: https://go-review.googlesource.com/c/go/+/639155
Reviewed-by: Sam Thanawalla <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Sam Thanawalla <[email protected]>

Author: seankhliao

src/cmd/go/alldocs.go

@@ -270,11 +270,7 @@ the go tool will verify that https://example.org/?go-get=1 contains the
 same meta tag and then git clone https://code.org/r/p/exproj into
 GOPATH/src/example.org.
 
-When using GOPATH, downloaded packages are written to the first directory
-listed in the GOPATH environment variable.
-(See 'go help gopath-get' and 'go help gopath'.)
-
-When using modules, downloaded packages are stored in the module cache.
+Downloaded packages are stored in the module cache.
 See https://golang.org/ref/mod#module-cache.
 
 When using modules, an additional variant of the go-import meta tag is

src/cmd/go/internal/help/helpdoc.go

@@ -125,11 +125,6 @@ suggested Go toolchain, see https://go.dev/doc/toolchain.
 
 For more about specifying packages, see 'go help packages'.
 
-This text describes the behavior of get using modules to manage source
-code and dependencies. If instead the go command is running in GOPATH
-mode, the details of get's flags and effects change, as does 'go help get'.
-See 'go help gopath-get'.
-
 See also: go build, go install, go clean, go mod.
 	`,
 }

src/cmd/go/internal/modget/get.go

@@ -3,4 +3,4 @@ env GO111MODULE=on
 # go help get shows usage for get
 go help get
 stdout 'usage: go get'
-stdout 'get using modules to manage source'
+stdout 'updates go.mod to require those versions'