Only use semverCompare with valid version strings

[westrik]

Handle image tags where the pre-release part of the semver version string contains a leading zero, e.g. 3.284.10-0360315.

Fix for errors like this:

Error: template: retool/templates/deployment_workflows.yaml:1:7: executing "retool/templates/deployment_workflows.yaml" at <include "retool.workflows.enabled" .>: error calling include: template: retool/templates/_helpers.tpl:254:109: executing "retool.workflows.enabled" at <semverCompare ">= 3.6.11-0" (regexFind $valid_retool_version_regexp $.Values.image.tag)>: error calling semverCompare: Version segment starts with 0