[ci] Strip any protocol prefix in the mirror diagnostic

The getent diagnostic stripped only https://, so an http:// mirror
override resolved nothing; ${mirror#*://} matches how
ci/bazel_mirror_downloader.sh extracts the host.

Signed-off-by: Thomas Desrosiers <thomas@anyscale.com>

Author: thomasdesr

ci/pypi_proxy_profile.sh

@@ -44,7 +44,7 @@ _rayci_pypi_index_setup() {
   # mirror is deployed and this fleet has no route to it". getent is Linux-only;
   # on macOS the address line is simply absent.
   local resolved
-  resolved="$(getent hosts "${mirror#https://}" 2>/dev/null | awk '{print $1}' | paste -sd, -)"
+  resolved="$(getent hosts "${mirror#*://}" 2>/dev/null | awk '{print $1}' | paste -sd, -)"
   echo "pypi index: mirror=${mirror} resolves_to=${resolved:-<unresolved>}"
 
   # Bazel's own downloader is a separate mechanism from pip's index and gets its