Update copyright notice and scripts/check_copyright.py script

[marcofavorito]

Proposed changes

• Update copyright notice end year: from 2022 to 2023
• Update scripts/check_copyright.py script (make it executable)

Fixes

n/a

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

Put an x in the boxes that apply.

• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works

Further comments

n/a

[codecov-commenter]

Codecov Report

Merging #62 (878c885) into main (75ecdf4) will not change coverage.
The diff coverage is n/a.

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@@           Coverage Diff           @@
##             main      #62   +/-   ##
=======================================
  Coverage   87.33%   87.33%           
=======================================
  Files          20       20           
  Lines        1050     1050           
  Branches      163      163           
=======================================
  Hits          917      917           
  Misses        104      104           
  Partials       29       29           

Flag	Coverage Δ
unittests	87.33% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pddl/__init__.py	100.00% <ø> (ø)
pddl/__main__.py	82.60% <ø> (ø)
pddl/__version__.py	100.00% <ø> (ø)
pddl/core.py	92.41% <ø> (ø)
pddl/custom_types.py	100.00% <ø> (ø)
pddl/exceptions.py	57.14% <ø> (ø)
pddl/formatter.py	98.07% <ø> (ø)
pddl/helpers/__init__.py	100.00% <ø> (ø)
pddl/helpers/base.py	93.75% <ø> (ø)
pddl/helpers/cache_hash.py	94.28% <ø> (ø)
... and 10 more

[francescofuggitti]

LGTM, thank you!