Move git user configuration to create_dot_gitconfig.local.tmpl

[arran4]

Move git user configuration to create_dot_gitconfig.local.tmpl

This removes the user name and email from dot_gitconfig.tmpl (leaving
only useConfigOnly = true under the [user] section) and adds the
templated name and email into create_dot_gitconfig.local.tmpl.
This ensures user configurations are correctly managed locally.

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PR created automatically by Jules for task 5088928759037547736 started by @arran4

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