Limit compatibility to Helm =>v3.0.0,<4.0.0 (#1039) (#1071)

This is a backport of PR #1039 as merged into main (13791ec).
SUMMARY
Helm v4 is a major version with backward-incompatible changes, including to the flags and output of the Helm CLI and to the SDK. This version is currently not supported in the kubernetes.core. This PR is related to #1038 and is a short-term solution to mark compatibility explicitly
ISSUE TYPE

Bugfix Pull Request
Docs Pull Request

COMPONENT NAME

helm
helm_template
helm_info
helm_repository
helm_pull
helm_registry_auth
helm_plugin
helm_plugin_info

ADDITIONAL INFORMATION
Added `validate_helm_version()`` method to AnsibleHelmModule that enforces version constraint >=3.0.0,<4.0.0.
Fails fast with clear error message: "Helm version must be >=3.0.0,<4.0.0, current version is {version}"
Some modules (i.e. helm_registry_auth) technically is compatible with Helm v4, but validation was added to all helm modules.
Partially coauthored by GitHub Copilot with Claude Sonnet 4 model.
Addresses issue #1038

Reviewed-by: Bianca Henderson <beeankha@gmail.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>

plugins/modules/helm_pull.py

@@ -21,7 +21,7 @@ description:
   - There are options for unpacking the chart after download.
 
 requirements:
-  - "helm >= 3.0 (https://github.com/helm/helm/releases)"
+  - "helm >= 3.0, <4.0.0 (https://github.com/helm/helm/releases)"
 
 options:
   chart_ref:
@@ -220,13 +220,10 @@ def main():
         mutually_exclusive=[("chart_version", "chart_devel")],
     )
 
+    # Validate Helm version >=3.0.0,<4.0.0
+    module.validate_helm_version()
+
     helm_version = module.get_helm_version()
-    if LooseVersion(helm_version) < LooseVersion("3.0.0"):
-        module.fail_json(
-            msg="This module requires helm >= 3.0.0, current version is {0}".format(
-                helm_version
-            )
-        )
 
     helm_pull_opt_versionning = dict(
         skip_tls_certs_check="3.3.0",