package/go: bump version to 1.15.11

go1.15.11 (released 2021/04/01) includes fixes to cgo, the compiler, linker,
runtime, the go command, and the database/sql and net/http packages

https://golang.org/doc/go1.15

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit abfb504eafa8bb94cf63b2ef669884fbbacc70db)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/go/go.hash

@@ -1,3 +1,3 @@
 # From https://golang.org/dl/
-sha256  c1dbca6e0910b41d61a95bf9878f6d6e93d15d884c226b91d9d4b1113c10dd65  go1.15.10.src.tar.gz
+sha256  f25b2441d4c76cf63cde94d59bab237cc33e8a2a139040d904c8630f46d061e5  go1.15.11.src.tar.gz
 sha256	2d36597f7117c38b006835ae7f537487207d8ec407aa9d9980794b2030cbc067  LICENSE

package/go/go.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GO_VERSION = 1.15.10
+GO_VERSION = 1.15.11
 GO_SITE = https://storage.googleapis.com/golang
 GO_SOURCE = go$(GO_VERSION).src.tar.gz