package/go: security bump to version 1.21.3

Fixes CVE-2023-39325: rapid stream resets can cause excessive work

A malicious HTTP/2 client which rapidly creates requests and immediately
resets them can cause excessive server resource consumption.  While the
total number of requests is bounded to the http2.Server.MaxConcurrentStreams
setting, resetting an in-progress request allows the attacker to create a
new request while the existing one is still executing.

go1.21.3 (released 2023-10-10) includes a security fix to the net/http
package.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Christian Stewart <christian@aperture.us>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/go/go.hash

@@ -1,3 +1,3 @@
 # From https://go.dev/dl
-sha256  45e59de173baec39481854490d665b726cec3e5b159f6b4172e5ec7780b2c201  go1.21.2.src.tar.gz
+sha256  186f2b6f8c8b704e696821b09ab2041a5c1ee13dcbc3156a13adcf75931ee488  go1.21.3.src.tar.gz
 sha256  2d36597f7117c38b006835ae7f537487207d8ec407aa9d9980794b2030cbc067  LICENSE

package/go/go.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GO_VERSION = 1.21.2
+GO_VERSION = 1.21.3
 GO_SITE = https://storage.googleapis.com/golang
 GO_SOURCE = go$(GO_VERSION).src.tar.gz