Use go mod proxy when building the release

This makes sure that the correct package version metadata
is included when inspected via `go version -m`.

Signed-off-by: Waldemar Quevedo <wally@nats.io>

.goreleaser.yml

@@ -1,5 +1,8 @@
 project_name: nats-server
 
+gomod:
+  proxy: true
+
 release:
   github:
     owner: nats-io
@@ -11,8 +14,10 @@ changelog:
   skip: true
 
 builds:
-- main: ./main.go
+- main: .
   binary: nats-server
+  flags:
+  - -trimpath
   ldflags:
     - -w -X github.com/nats-io/nats-server/v2/server.gitCommit={{.ShortCommit}}
   env: