Handle Missing Namespace

[mfl-code]

Description

When a namespace is in the state file, but not in the temporal server, applying the namespace return an error.

Way to reproduce problem:

• In one window, run the server with temporal server start-dev
• In another window run temporal apply. Remove old .terraform* files if exists.
• Stop and restart the server in the firs windw.
• In the second window run temporal apply again. You will get an error/

After the fix, the namespace would be re-added.

Read the Contribution guidelines.

• Generate the docs.
• Run the relevant tests successfully.
• Include release notes. If this PR is backward incompatible, include a migration guide.

[ganievs]

Hi @mfl-code! The issue occurs when the Terraform state file contains information about a namespace that no longer exists in the Temporal server, often due to server restarts or manual deletions.
Instead of automatically removing resources from state, which can lead to unexpected behavior and potential data loss, it's recommended to use terraform state rm.

[mfl-code]

@ganievs I removed the deletion from the state. This is still a fix for when the namespace is missing from the server, and "terraform apply" will work now.