Fix tests, README links

[DrShushen]

Description

This PR:

• Fixes the pre-commit run failure due to pydantic version (pydantic<2 for now).
• Fixes broken tutorial links in README.
• Work around a pandera/pandas compatibility issue in MultiIndex case (reported here MultiIndex unique columns case - pandas error instead of (expected) schema error when pandas version 2.1.0 unionai-oss/pandera#1328).
• Fix test failure due to running out of space during pip install with python 3.7 - use legacy pip resolver.

Affected Dependencies

• catboost < 1.2 requirement removed as it no longer causes problems in runners.
• Specify typing-extensions >= 4.7.1 so that installation works with pip legacy resolver.
• Specify joblib < 1.3.0; python_version=="3.7" and platform_system=="Windows" to avoid error module '_winapi' has no attribute 'SYNCHRONIZE' on python 3.7 with windows and joblib 1.3.0 due to loky joblib/loky#411

How has this been tested?

N/A

Checklist

• I have followed the Contribution Guidelines and Code of Conduct
• I have commented my code following the van der Schaar Lab Styleguide
• I have labelled this PR with the relevant Type labels
• My changes are covered by tests

[codecov]

Codecov Report

Patch coverage: 68.75% and project coverage change: -0.09% ⚠️

Comparison is base (67ebd74) 100.00% compared to head (d0dab45) 99.91%.

❗ Current head d0dab45 differs from pull request most recent head 9649398. Consider uploading reports for the commit 9649398 to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##              main      #72      +/-   ##
===========================================
- Coverage   100.00%   99.91%   -0.09%     
===========================================
  Files          107      107              
  Lines         5886     5901      +15     
  Branches       694      695       +1     
===========================================
+ Hits          5886     5896      +10     
- Misses           0        5       +5     

Flag	Coverage Δ
test	99.91% <68.75%> (-0.09%)	⬇️
test_full	?

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

Files Changed	Coverage Δ
src/tempor/benchmarks/benchmark.py	100.00% <ø> (ø)
src/tempor/benchmarks/evaluation.py	100.00% <ø> (ø)
src/tempor/benchmarks/utils.py	100.00% <ø> (ø)
src/tempor/models/ddh.py	100.00% <ø> (ø)
src/tempor/utils/dataloaders/sine.py	100.00% <ø> (ø)
src/tempor/data/samples.py	98.21% <68.75%> (-1.79%)	⬇️

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.