hack: update link to GOPATH documentation

This documentation moved to a different page, and the Go documentation
moved to the https://go.dev/ domain.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 2aabd6447753bde5c844b2549cd2330cb1383bb6)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/make.ps1

@@ -459,7 +459,7 @@ Try {
     if (-not $inContainer) { Verify-GoVersion }
 
     # Verify GOPATH is set
-    if ($env:GOPATH.Length -eq 0) { Throw "Missing GOPATH environment variable. See https://golang.org/doc/code.html#GOPATH" }
+    if ($env:GOPATH.Length -eq 0) { Throw "Missing GOPATH environment variable. See https://pkg.go.dev/cmd/go#hdr-GOPATH_environment_variable" }
 
     # Run autogen if building daemon.
     if ($Daemon) {

hack/make.sh

@@ -79,7 +79,7 @@ if [ "$AUTO_GOPATH" ]; then
 fi
 
 if [ ! "$GOPATH" ]; then
-	echo >&2 'error: missing GOPATH; please see https://golang.org/doc/code.html#GOPATH'
+	echo >&2 'error: missing GOPATH; please see https://pkg.go.dev/cmd/go#hdr-GOPATH_environment_variable'
 	echo >&2 '  alternatively, set AUTO_GOPATH=1'
 	exit 1
 fi