tools/syz-env: support GOPROXY environment variable

Working in a firewalled environment where Go proxy services are blocked.
To work around this, we need to set GORPOXY=direct in order to make go
builds download packages directly from source rather than using a proxy.
Support such setups by passing the user's GOPROXY setting into the
syz-env Docker container.

Signed-off-by: Bjoern Doebel <doebel@amazon.de>

Author: bjoernd

tools/syz-env

@@ -94,6 +94,7 @@ docker run \
 	--workdir /syzkaller/gopath/src/github.com/google/syzkaller \
 	--env HOME=/syzkaller \
 	--env GOPATH=/syzkaller/gopath:/gopath \
+	--env GOPROXY \
 	--env FUZZIT_API_KEY \
 	--env GITHUB_REF \
 	--env GITHUB_SHA \