fix(go): Disable the GOPATH mode to fix the fun tests

Recently, the fun tests for `GoDep` started failing which was roughly
at the same time as the major version upgrade to 1.22.0 in ORT's docker
image. As the GOPATH mode will eventually be removed ^[1], just disable
it now to fix the tests. In particular, do so even though the root cause
of the failing tests is unkown, as `GoDep` is rather outdated and thus
cannot satisfy putting in further efforts.

[1]: golang/go#41330 (comment)

Signed-off-by: Frank Viernau <[email protected]>

plugins/package-managers/go/src/main/kotlin/GoDep.kt

@@ -266,7 +266,7 @@ private fun resolveProjectRoot(definitionFile: File) =
 private fun resolveVcsInfo(importPath: String, revision: String, gopath: File): VcsInfo {
     val pc = ProcessCapture(
         "go", "get", "-d", importPath,
-        environment = mapOf("GOPATH" to gopath.path, "GO111MODULE" to "off")
+        environment = mapOf("GOPATH" to gopath.path)
     )
 
     // HACK Some failure modes from "go get" can be ignored: