🐛 Force IPv4 in 05-custom.sh to fix GitHub API SSL failure 🐛

The casjaysdev/alpine base image routes *.github.com IPv6 addresses through
casjay.in infrastructure, which presents CN=casjay.in instead of GitHub's
certificate. curl -fsSL to api.github.com resolves to 2402:d0c0:12:e04e::1
and fails with "no alternative certificate subject name matches target
hostname api.github.com". Standard alpine:latest uses the IPv4 address
140.82.114.6 and succeeds.
Fix: write "-4" to /root/.curlrc at the top of 05-custom.sh so every curl
call in the script (including the golangci-lint installer sub-script) uses
IPv4. Build now completes successfully.
- rootfs/root/docker/setup/05-custom.sh: add printf '-4' > /root/.curlrc
before any network calls

rootfs/root/docker/setup/05-custom.sh

rootfs/root/docker/setup/05-custom.sh

@@ -22,6 +22,9 @@
 # Set bash options
 set -eo pipefail
 [ "$DEBUGGER" = "on" ] && echo "Enabling debugging" && set -x$DEBUGGER_OPTIONS
+# Force IPv4 for all curl calls in this script — the base image IPv6 routing
+# intercepts *.github.com and presents a cert for casjay.in, causing SAN mismatch
+printf -- '-4\n' > /root/.curlrc
 # - - - - - - - - - - - - - - - - - - - - - - - - -
 # Set env variables
 exitCode=0