chore(master): backfill missing copyright years in source file headers

[tiborsimko]

Many file headers have gaps in their copyright year list: a file was modified in a given year, but that year was never added. For example, a header reads Copyright (C) 2019, 2024 CERN. while git log shows edits in 2020–2023 too.

Let us update each source code file to backfill missing years. And let's check each repository top-level LICENSE file too.

• chore(master): backfill missing copyright years blog.reana.io#60
• chore(master): backfill missing copyright years docs.reana.io#227
• chore(master): backfill missing copyright years #974
• chore(master): backfill missing copyright years reana-auth-krb5#23
• chore(master): backfill missing copyright years reana-auth-rucio#22
• chore(master): backfill missing copyright years reana-auth-vomsproxy#38
• chore(master): backfill missing copyright years reana-client#776
• chore(master): backfill missing copyright years reana-client-go#183
• chore(master): backfill missing copyright years reana-commons#544
• chore(master): backfill missing copyright years reana-dask-kubernetes-operator#15
• chore(master): backfill missing copyright years reana-db#268
• chore(master): backfill missing copyright years reana-demo-agc-cms-ttbar-coffea#11
• chore(master): backfill missing copyright years reana-demo-alice-lego-train-test-run#36
• chore(master): backfill missing copyright years reana-demo-atlas-recast#60
• chore(master): backfill missing copyright years reana-demo-bsm-search#44
• chore(master): backfill missing copyright years reana-demo-cdci-crab-pulsar-integral-verification#24
• chore(master): backfill missing copyright years reana-demo-cdci-integral-data-reduction#11
• chore(master): backfill missing copyright years reana-demo-cms-dimuon-mass-spectrum#26
• chore(master): backfill missing copyright years reana-demo-cms-h4l#42
• chore(master): backfill missing copyright years reana-demo-cms-reco#44
• chore(master): backfill missing copyright years reana-demo-dask-coffea#4
• chore(master): backfill missing copyright years reana-demo-fcchh-fullsim#17
• chore(master): backfill missing copyright years reana-demo-lhcb-d2pimumu#24
• chore(master): backfill missing copyright years reana-env-jupyter#27
• chore(master): backfill missing copyright years reana-env-root6#32
• chore(master): backfill missing copyright years reana-github-actions#16
• chore(master): backfill missing copyright years reana-job-controller#524
• chore(master): backfill missing copyright years reana-message-broker#84
• chore(master): backfill missing copyright years reana-server#788
• chore(master): backfill missing copyright years reana-ui#515
• chore(master): backfill missing copyright years reana-workflow-controller#691
• chore(master): backfill missing copyright years reana-workflow-engine-cwl#318
• chore(master): backfill missing copyright years reana-workflow-engine-serial#248
• chore(master): backfill missing copyright years reana-workflow-engine-snakemake#131
• chore(master): backfill missing copyright years reana-workflow-engine-yadage#305
• chore(master): backfill missing copyright years reana-workflow-validator#6
• chore(master): backfill missing copyright years www.reana.io#101