[release] src/goLanguageServer: add platfom info in the automated issue report

Change-Id: I74fa5d8205102251bc6403f7a73691439f4e9944
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/289369
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>

Author: hyangah

src/goLanguageServer.ts

@@ -1344,7 +1344,7 @@ Failed to auto-collect gopls trace: ${failureReason}.
 gopls version: ${usersGoplsVersion}
 gopls flags: ${settings}
 extension version: ${extInfo.version}
-environment: ${extInfo.appName}
+environment: ${extInfo.appName} ${process.platform}
 initialization error: ${initializationError}
 manual restart count: ${manualRestartCount}
 total start count: ${totalStartCount}