Inherit `DEFAULT_CHUNK_SPLIT_NS` from strax

[dachengx]

Before you submit this PR: make sure to put all operations-related information in a wiki-note, a PR should be about code and is publicly accessible

What does the code in this PR do / what does it improve?

Depends on https://github.com/AxFoundation/strax/pull/865, where the minimum allowed splitting of chunk is DEFAULT_CHUNK_SPLIT_NS. This PR also temporarily uses the latest strax to be compatible with the latest codes.

Can you briefly describe how it works?

Can you give a minimal working example (or illustrate with a figure)?

Please include the following if applicable:

• [ ] Update the docstring(s)
• [ ] Update the documentation
• [ ] Tests to check the (new) code is working as desired.
• [ ] Does it solve one of the open issues on github?

Notes on testing

• Until the automated tests pass, please mark the PR as a draft.
• On the XENONnT fork we test with database access, on private forks there is no database access for security considerations.

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[coveralls]

coverage: 91.156% (+0.02%) from 91.135% when pulling 77b0de348332941952a2485c09b0cdddf1493bc5 on inherit_safe_break_in_pulses into 56220278394a6a62182eccd8536d64dacaab41d5 on master.