fix(fabric): correct shared job template image vars

[malsomesh9]

Summary

Fix the Fabric minikube deployment regressions from issue #2659 that are still reproducible in the shared job component templates.

Changes

• update the Fabric genesis/channel job templates to read fabric_tools_image and bevel_alpine_version from charts.*, which matches how these values are defined in the shared role vars
• remove the unconditional update_repo_cache: true from the shared Helm install task so local/chart-path installs do not fail when no Helm repo has been added

Notes

• the create-join-channel.yaml playbook paths referenced in the report still exist in the current tree, so this PR keeps scope to the two concrete repo-level failures I could confirm directly

Fixes #2659