Version 4: Change current v3 branch names to include "v3"

### Summary
Update the branches which are currently called `develop` and `main` to include "v3" in the name, e.g. "v3.0.0/develop" and "v3.0.0/main".

### 💬 Description
As we will be creating v4 develop and main branches (probably called "v4.0.0/develop" and "v4.0.0/main"), we will want to update our branches which are currently called "develop" and "main" (i.e. v3 branches) to include "v3" in their names, e.g. "v3.0.0/main" and "v3.0.0/develop".

This ticket is to change the names plus any references to the branch names in any workflows i.e. make sure the v3 workflows continue to work correctly.

Search the repository's workflow files and references to the current develop and main branches. Identify every v3 reference that must use the proposed v3.0.0/develop and v3.0.0/main names, then verify that the v3 workflows continue to work with the renamed branches.

Written by the indexing model from the issue text.