Make CI work (#8057)

* Use export GOPROXY=https://goproxy.cn before build

* Add go version to generate command

* Reproduced the entire build procedure - see notes

I've used:

sudo go clean -i -r -cache -testcache -modcache
make clean
make generate
make golangci-lint
make revive
make swagger-check
make swagger-validate
make test-vendor            <--- this now fails
make vendor                 <--- this now produced changes
git commit -a               <--- this commit

* Add fix from #8059 to complete CI tests

vendor/golang.org/x/sys/unix/mkerrors.sh

@@ -206,6 +206,7 @@ struct ltchars {
 #include <linux/netfilter/nfnetlink.h>
 #include <linux/netlink.h>
 #include <linux/net_namespace.h>
+#include <linux/nsfs.h>
 #include <linux/perf_event.h>
 #include <linux/random.h>
 #include <linux/reboot.h>
@@ -451,6 +452,7 @@ ccflags="$@"
 		$2 ~ /^SYSCTL_VERS/ ||
 		$2 !~ "MNT_BITS" &&
 		$2 ~ /^(MS|MNT|UMOUNT)_/ ||
+		$2 ~ /^NS_GET_/ ||
 		$2 ~ /^TUN(SET|GET|ATTACH|DETACH)/ ||
 		$2 ~ /^(O|F|[ES]?FD|NAME|S|PTRACE|PT)_/ ||
 		$2 ~ /^KEXEC_/ ||