fix(mistral): match Pixtral and Mixtral models

[Kcstring]

Fixes #124.

Summary

• Extend the Mistral provider-level model matcher to include Pixtral and Mixtral model names.
• Add a regression test that resolves Pixtral and Mixtral models without an explicit provider id.
• Regenerate package data for Python, JS, and JSON outputs.

Tests

• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package prices -m prices build
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package prices -m prices package_data
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package prices -m prices inject_providers
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package genai-prices pytest tests/test_model_matching.py -k "mistral_model_match or pixtral or mixtral"
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package genai-prices pytest tests/test_price_calc.py -k "mistral and pixtral"
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run --package genai-prices genai-prices calc --input-tokens 10000 --output-tokens 10000 pixtral-12b-latest mixtral-8x7b-instruct-v0.1
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run ruff check tests/test_model_matching.py packages/python/genai_prices/data.py
• env UV_CACHE_DIR=/tmp/uv-cache UV_PYTHON_INSTALL_DIR=/tmp/uv-python uv run ruff format --check tests/test_model_matching.py packages/python/genai_prices/data.py

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 2 additional findings.

[alexmojaki]

need to resolve merge conflicts in generated files now