Prompts to update gopls as and when a new stable version is out

[ramya-rao-a]

In 0.11.5, we introduced a feature where the extension prompts users to update their gopls if it was found to be out of date when compared to the latest stable version.

This was done by making calls to https://proxy.golang.org

This approach has a couple of concerns

• The call would fail for users behind corporate or private proxies or in China. See language server(gopls) not working #2768
• Users might have their own GOPROXY set up in which case that is what should be respected
• Some users might not want such outgoing calls and so would want a way to turn it off.

In 0.11.6, we are no longer making such outgoing calls and have instead hard-coded the currently known latest version of gopls in the check that results in the prompt to update gopls

This issue is to discuss next steps that will allow us to prompt users to update gopls as and when a new stable version is out while keeping the above concerns in mind

cc @stamblerre

[ramya-rao-a]

Current proposals:

• Add a setting so that user can opt out of such outgoing calls. See Gate the check for gopls updates using a setting #2773
• if user has configured GOPROXY, use that. See use the user's GOPROXY settings when requesting the gopls version #2774

[stamblerre]

I think the combination of the two current proposals will be sufficient to make sure that the user has enough control over the auto-updating behavior. The go command will make requests to GOPROXY when VSCode runs go get to install packages, so this will behave in a similar fashion. The setting adds another level of protection, so if a user doesn't want the auto-updating behavior, it can be turned off. This sounds pretty solid to me. What do you think, @ramya-rao-a?

[ramya-rao-a]

The latest beta version of the extension has this feature where the GOPROXY is used to determine whether a newer update is available. This can be disabled using the new setting go.useGoProxyToCheckForToolUpdates