ci(versions): use full variable name in cozy-installer report label

Address review feedback from gemini-code-assist on hack/check-versions.sh:
use the full `cozystack_chart_version` name (matching the actual key in
roles/cozystack/defaults/main.yml) instead of the abbreviated
`chart_version` so a DRIFT report points directly at the variable to
inspect.

Assisted-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>

Author: lexfrei

hack/check-versions.sh

@@ -75,7 +75,7 @@ cozy_ubuntu=$(strip_v "$(get_collection_version examples/ubuntu/requirements.yml
 
 report "cozy-installer" \
   "galaxy.yml:version"                                "$cozy_galaxy" \
-  "roles/cozystack/defaults/main.yml:chart_version"   "$cozy_role" \
+  "roles/cozystack/defaults/main.yml:cozystack_chart_version" "$cozy_role" \
   "examples/rhel/requirements.yml"                    "$cozy_rhel" \
   "examples/suse/requirements.yml"                    "$cozy_suse" \
   "examples/ubuntu/requirements.yml"                  "$cozy_ubuntu" \