add license hook to pre-commit

[Ariana-B]

Reason for this pull request

See #1310

Proposed changes

• Add pre-commit hook to check for license header in python files located in core subdirectories

• Closes Add a pre-commit hook to verify license headers #1310

• Tests added / passed

• Fully documented, including docs/about/whats_new.rst for all changes

---

📚 Documentation preview 📚: https://datacube-core--1438.org.readthedocs.build/en/1438/

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (082933f) 91.84% compared to head (df7f48f) 91.84%.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #1438   +/-   ##
========================================
  Coverage    91.84%   91.84%           
========================================
  Files          132      132           
  Lines        14466    14466           
========================================
  Hits         13286    13286           
  Misses        1180     1180           

Impacted Files	Coverage Δ
datacube/__init__.py	100.00% <ø> (ø)
datacube/api/__init__.py	100.00% <ø> (ø)
datacube/api/core.py	95.64% <ø> (ø)
datacube/api/grid_workflow.py	97.05% <ø> (ø)
datacube/api/query.py	93.71% <ø> (ø)
datacube/config.py	97.61% <ø> (ø)
datacube/drivers/__init__.py	100.00% <ø> (ø)
datacube/drivers/_tools.py	100.00% <ø> (ø)
datacube/drivers/_types.py	100.00% <ø> (ø)
datacube/drivers/datasource.py	100.00% <ø> (ø)
... and 120 more

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[SpacemanPaul]

239 files changed??!?! Ai yai yai!!!

Oh right, I see.

Needs a whats_new.rst entry, otherwise all good.

[Ariana-B]

Needs a whats_new.rst entry, otherwise all good.

Whoops! Thought I'd done that but clearly not. Done.