Allow spectrum collection slices to exceed length

[ajjackson]

Closes #407

Following established conventions for python list and numpy array, if a slice exceeds the array length the result can quietly return up to the last available item. This allows things like [:10] to mean "up to first ten items" which is nice for printing etc.

As discussed in #407 this might be a dubious API break. But it's difficult to see the real-world harm.

[github-actions]

Test Results

    26 files   -     8      26 suites   - 8   1h 42m 6s ⏱️ - 3h 1m 32s
 1 111 tests  -     1   1 105 ✅  -     1   6 💤 ± 0  0 ❌ ±0 
15 341 runs   - 8 439  15 255 ✅  - 8 400  86 💤  - 39  0 ❌ ±0 

Results for commit 0b79fc6. ± Comparison against base commit 22772b7.

This pull request removes 1 test.

tests_and_analysis.test.euphonic_test.test_spectrum1dcollection.TestSpectrum1DCollectionIndexAccess ‑ test_index_errors[spectrum3-index3-IndexError]

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.26%. Comparing base (22772b7) to head (0b79fc6).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #422      +/-   ##
==========================================
- Coverage   97.26%   97.26%   -0.01%     
==========================================
  Files          32       32              
  Lines        4312     4307       -5     
  Branches      635      633       -2     
==========================================
- Hits         4194     4189       -5     
  Misses         70       70              
  Partials       48       48              

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[ajjackson]

As this is quite low priority and technically breaking, let's defer it until Euphonic 2.0.

Let's also not wait too long to make Euphonic 2.0. API-breaking version numbers don't have to be major "political" releases, that is a trap larger projects often fall into.