add configuration and custom generator for jet-jet gap trigger setup

[jaimenorman]

add custom generator for jet-jet production with a MB gap
Includes custom generator which generates N MB events for every jet-jet event (N is configurable)
jet-jet and MB PYTHIA .cfg configuration files are also included

[github-actions]

REQUEST FOR PRODUCTION RELEASES:
To request your PR to be included in production software, please add the corresponding labels called "async-" to your PR. Add the labels directly (if you have the permissions) or add a comment of the form (note that labels are separated by a ",")

+async-label <label1>, <label2>, !<label3> ...

This will add <label1> and <label2> and removes <label3>.

The following labels are available
async-2023-pbpb-apass4
async-2023-pp-apass4
async-2024-pp-apass1
async-2022-pp-apass7
async-2024-pp-cpass0
async-2024-PbPb-apass1
async-2024-ppRef-apass1

[jaimenorman]

+async-label async-2022-pp-apass7 async-2023-pp-apass4 async-2023-pbpb-apass4 async-2024-pp-apass1 async-2024-PbPb-apass1 async-2024-ppRef-apass1

[github-actions]

Hi @jaimenorman, the following label names could not be recognised: async-2022-pp-apass7 async-2023-pp-apass4 async-2023-pbpb-apass4 async-2024-pp-apass1 async-2024-PbPb-apass1 async-2024-ppRef-apass1

[jaimenorman]

+async-label async-2022-pp-apass7, async-2023-pp-apass4, async-2023-pbpb-apass4, async-2024-pp-apass1, async-2024-PbPb-apass1, async-2024-ppRef-apass1

[sawenzel]

@jaimenorman : We no longer require backporting of generator configs to past tags as explained in https://its.cern.ch/jira/browse/O2-5366. Could you check if the mechanism is usable for you?

@alcaliva : I am not sure, but potentially we back-port alisw/alidist#5681 to all of our productions tags so that this feature is available in productions.

[jaimenorman]

@sawenzel thanks for the information, I think what you describe would work for us.
Would you be able to approve so that I can test with this config? I think we are pretty much ready to go to production with this config.

[sawenzel]

Removed labels.