Modernise code for Python 3.9+

Following up from modernisations at !917 (merged) and addition of pre-commit hooks to the offline stack.

added enhancement modernisation labels

requested review from @pkoppenb

assigned to @erodrigu

All nice and easy. Let me run a test immediately to get this merged asap (I think acceptable for a trivial MR) :-).

/ci-test --platform=x86_64_v2-centos7-gcc11-opt

added ci-test-triggered label

mentioned in merge request Analysis!994 (merged)

• [2023-06-28 13:27] Validation started with lhcb-master-mr#8389
• [2023-06-28 18:06] Validation started with lhcb-master-mr#8399

And that will work on all platforms? (I am not following the evolution of python versions...)

approved this merge request

added 1 commit

• 7785dcb7 - Ran pyupgrade for Python 3.9+

Compare with previous version

As per your desire :-) :

/ci-test Analysis!994 (merged)

resolved all threads

resolved all threads

merged

mentioned in commit 46354f4d