Octo Component management tab is enabled by default in all team-managed (former next-gen) projects and the component version field is available by default in all Jira projects. There is an option to disable these features in each project separately.
How to disable Octo in a specific project
Go to:
In company-managed (former classic) projects: Project settings > Octo Component Management
In team-managed(next-gen) projects: Project settings > Apps > Octo Component Management
Uncheck toggle Enable/Disable Octo Component Management app in this project
The Component version field and Octo tab are now hidden from the Project menu and issue detail.