Drop remote_development_agent_configs table

What does this MR do and why?

We switched to the new table workspaces_agent_configs which replaces the remote_development_agent_configs table, the data was already migrated and application code references updated with this MR: Migrate remote_development_agent_configs table (!163846 - merged)

This is a follow up to delete remote_development_agent_configs as it is not used anymore

MR acceptance checklist

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• remote_development_agent_configs table is deleted
• db/docs/remote_development_agent_configs.yml is moved to deleted_tables directory

Screenshots or screen recordings

This MR does not contain any UI changes

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