Add missing headers and update copyright years

[samoht]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1961 (5c5a10d) into main (46c79a8) will decrease coverage by 0.03%.
The diff coverage is n/a.

❗ Current head 5c5a10d differs from pull request most recent head 4bf62fc. Consider uploading reports for the commit 4bf62fc to get more accurate results

@@            Coverage Diff             @@
##             main    #1961      +/-   ##
==========================================
- Coverage   63.96%   63.93%   -0.04%     
==========================================
  Files         130      130              
  Lines       15479    15479              
==========================================
- Hits         9901     9896       -5     
- Misses       5578     5583       +5     

Impacted Files	Coverage Δ
bench/irmin-pack/bench_common.ml	20.98% <ø> (ø)
bench/irmin-pack/trace_collection.ml	83.75% <ø> (ø)
bench/irmin-pack/trace_common.ml	87.50% <ø> (ø)
bench/irmin-pack/trace_definitions.ml	62.06% <ø> (ø)
bench/irmin-pack/trace_replay.ml	43.26% <ø> (ø)
bench/irmin-pack/trace_stat_summary.ml	83.90% <ø> (ø)
bench/irmin-pack/trace_stat_summary_pp.ml	0.18% <ø> (ø)
bench/irmin-pack/trace_stat_summary_utils.ml	60.00% <ø> (ø)
src/irmin-chunk/irmin_chunk.ml	77.67% <ø> (ø)
src/irmin-cli/cli.ml	20.74% <ø> (ø)
... and 102 more

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