Manual restore of sub-module required after ioc-template updates

[gilesknap]

This is because the ioc-template CI commits changes to this repo using
https://github.com/epics-containers/ioc-template/blob/4a13ff058db9212cb5328c19b42c48ab3e7f375f/.github/workflows/_example.yml#L29-L38

This does not honour the sub-module, instead adding it as a folder in the repo.

Current workaround is to clone this repo,

git submodule add https://github.com/epics-containers/ibek-support.git

and push back to main.

Leaving as a manual workaround for now as it's sort of a useful reminder to verify that this example represents what we changed in ioc-template. (plus I don't know how to fix it yet)

[gilesknap]

Last time I did this I had to do instead:

git submodule add --force https://github.com/epics-containers/ibek-support.git