sdk.bzl: include go.env since 1.21.0

[sluongng]

Include go.env file in the root of the sdk repo starting from Go 1.21.0.

Fixes #3665

[sluongng]

!master ~/work/bazelbuild/rules_go> cat /private/var/tmp/_bazel_sluongng/5c02d8a9b82454292bdfef7b6f9ac04e/external/go_sdk/go.env
# This file contains the initial defaults for go command configuration.
# Values set by 'go env -w' and written to the user's go/env file override these.
# The environment overrides everything else.

# Use the Go module mirror and checksum database by default.
# See https://proxy.golang.org for details.
GOPROXY=https://proxy.golang.org,direct
GOSUMDB=sum.golang.org

# Automatically download newer toolchains as directed by go.mod files.
# See https://go.dev/doc/toolchain for details.
GOTOOLCHAIN=auto

for reference, this is the content of the file.

[fmeum]

@sluongng Could you submit the update to Go SDK 1.21.0 combined with the revert of the earlier approach to fix the GO_PROXY issue? The work should be done and that way we can test that's actually the case.

Thank you very much for driving these fixes!

[sluongng]

I don't think we need a revert on Gazelle side just yet.

Instead, let's proceed with the Go SDK upgrade in rules_go.
Once rules_go is updated, we shall bump rules_go + GoSDK version in Gazelle and revert the change.

WDYT?

[sluongng]

Here is the revert on Gazelle side anyway ☝️

You already have your PR for bumping Go SDK in rules_go. Let's try merging that @fmeum