feat: update Go to 1.21.3

Use the latest pkgs version.

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

Pkgfile

@@ -4,7 +4,7 @@ format: v1alpha2
 
 vars:
   PKGS_PREFIX: ghcr.io/siderolabs
-  PKGS_VERSION: v1.6.0-alpha.0-20-g0c84090
+  PKGS_VERSION: v1.6.0-alpha.0-22-g37348d6
 
   # renovate: datasource=git-refs versioning=git depName=https://github.com/awslabs/tc-redirect-tap.git
   tc_redirect_tap_ref: 706117b1e02a532f7dadab3d9704f34521a0eac9