[release] update LICENSE for v0.38.0

Change-Id: Icff82b7a6e1e0479241c6fabf83fed7a9c16b8b4
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/470435
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
TryBot-Result: kokoro <[email protected]>
Run-TryBot: Suzy Mueller <[email protected]>

Author: suzmue