package/go: security bump to v1.21.5

Fixes the following CVEs:

CVE-2023-39326: net/http: limit chunked data overhead
CVE-2023-45285: cmd/go: go get may unexpectedly fallback to insecure git

https://go.dev/doc/devel/release#go1.21.5

Signed-off-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  47b26a83d2b65a3c1c1bcace273b69bee49a7a7b5168a7604ded3d26a37bd787  go1.21.4.src.tar.gz
+sha256  285cbbdf4b6e6e62ed58f370f3f6d8c30825d6e56c5853c66d3c23bcdb09db19  go1.21.5.src.tar.gz
 sha256  2d36597f7117c38b006835ae7f537487207d8ec407aa9d9980794b2030cbc067  LICENSE

package/go/go.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GO_VERSION = 1.21.4
+GO_VERSION = 1.21.5
 GO_SITE = https://storage.googleapis.com/golang
 GO_SOURCE = go$(GO_VERSION).src.tar.gz