🧪 Improve schema process benchmarking

[chrisjsewell]

Have standard test, to make sure the build works, and separate benchmark test.

The standard test runs during standard testing, e.g. running tox,
and the benchmark test can be run using e.g. tox -e py312-benchmark -- tests/benchmarks/test_schema_benchmark.py --benchmark-columns=min,max,mean

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Current results on my MacBook:

--------------------------------------- benchmark: 4 tests --------------------------------------
Name (time in ms)                       Min                   Max                  Mean          
-------------------------------------------------------------------------------------------------
test_schema_benchmark[10]            3.7598 (1.0)          3.8571 (1.0)          3.8040 (1.0)    
test_schema_benchmark[100]          34.5185 (9.18)        36.2754 (9.40)        35.2756 (9.27)   
test_schema_benchmark[1000]        359.5095 (95.62)      404.7844 (104.95)     375.7929 (98.79)  
test_schema_benchmark[10000]     3,766.5854 (>1000.0)  4,034.7065 (>1000.0)  3,875.5382 (>1000.0)
-------------------------------------------------------------------------------------------------

[Copilot]

Pull request overview

This PR restructures the schema benchmark testing to separate functional validation from performance benchmarking. The benchmark project setup is extracted into a reusable fixture (schema_benchmark_app) in conftest.py, enabling both standard tests that verify build correctness and dedicated benchmark tests that measure schema processing performance.

Key changes:

• Extracted benchmark project setup into a reusable fixture
• Added standard test in test_schema.py that runs during normal testing
• Simplified benchmark test to focus on performance measurement
• Moved snapshot assertions to the standard test

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/schema/test_schema.py	Adds standard test that validates the benchmark project builds successfully using snapshot assertions
tests/schema/snapshots/test_schema.ambr	Contains new snapshot data for the standard benchmark test validation
tests/conftest.py	Introduces schema_benchmark_app fixture that dynamically generates benchmark projects with configurable need counts
tests/benchmarks/test_schema_benchmark.py	Simplified to focus on performance benchmarking using pytest-benchmark, removing project setup logic
tests/benchmarks/__snapshots__sphinx_lt_8/test_schema_benchmark.ambr	Removed as snapshot assertions moved to standard test
tests/benchmarks/__snapshots__sphinx_ge_8/test_schema_benchmark.ambr	Removed as snapshot assertions moved to standard test

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.94%. Comparing base (4e10030) to head (242ff54).
⚠️ Report is 198 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1579      +/-   ##
==========================================
+ Coverage   86.87%   87.94%   +1.06%     
==========================================
  Files          56       70      +14     
  Lines        6532     9630    +3098     
==========================================
+ Hits         5675     8469    +2794     
- Misses        857     1161     +304     

Flag	Coverage Δ
pytests	87.94% <ø> (+1.06%)	⬆️

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[ubmarco]

LGTM