ci: Set explicit base-branch for codecov action

[ericapisani]

Summary

• Explicitly sets base-branch: master on the getsentry/codecov-action step in all test-integration workflows
• The change is made in the Jinja template (scripts/split_tox_gh_actions/templates/test_group.jinja) and all 15 workflow files are regenerated
• Fixes codecov's auto-detection of the default branch failing, which caused incorrect coverage comparisons on PRs (see https://github.com/getsentry/sentry-python/actions/runs/24350025657/job/71101512671?pr=5978)

Refs PY-2295 and fixes #5991

Test plan

• Verify codecov coverage checks run correctly against master on this PR

🤖 Generated with Claude Code

[linear-code]

PY-2295 Set base-branch in configuration for code-cov github action

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

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New Features ✨

• (ai) Redact base64 data URLs in image_url content blocks by ericapisani in #5953
• (integrations) Instrument pyreqwest tracing by servusdei2018 in #5682
• (litellm) Add async callbacks by alexander-alderman-webb in #5969

Bug Fixes 🐛

Anthropic

• Capture exceptions for stream() calls by alexander-alderman-webb in #5950
• Stop setting transaction status when child span fails by alexander-alderman-webb in #5717
• Only finish relevant spans in .create() patches by alexander-alderman-webb in #5716

Pydantic Ai

• Adapt import for new library versions by alexander-alderman-webb in #5984
• Use first-class hooks when available by alexander-alderman-webb in #5947

Other

• (huggingface_hub) Stop setting transaction status when a child span fails by Zenithatic in #5952
• (litellm) Avoid double span exits when streaming by alexander-alderman-webb in #5933
• (wsgi) Respect HTTP_X_FORWARDED_PROTO in request.url construction by sl0thentr0py in #5963

Internal Changes 🔧

Litellm

• Replace mocks with httpx types in rate-limit test by alexander-alderman-webb in #5975
• Replace mocks with httpx types in embedding tests by alexander-alderman-webb in #5970
• Replace mocks with httpx types in nonstreaming completion() tests by alexander-alderman-webb in #5937
• Remove dead attributes by alexander-alderman-webb in #5985

Other

• (ai) Remove gen_ai.tool.type span attribute by ericapisani in #5964
• (anthropic) Separate sync and async .create() patches by alexander-alderman-webb in #5715
• (openai) Split token counting by API for easier deprecation by ericapisani in #5930
• (openai-agents) Remove error attributes by alexander-alderman-webb in #5986
• (opentelemetry) Ignore mypy error by alexander-alderman-webb in #5927

• Set explicit base-branch for codecov action by ericapisani in #5992

• 🤖 Update test matrix with new releases (04/13) by github-actions in #5983
• Fix license metadata in setup.py by sl0thentr0py in #5934
• Update validate-pr workflow by stephanie-anderson in #5931

Other

• Handle None span context in the span processor and pin tokenizers version for anthropic tests on Python 3.8 by alexander-alderman-webb in #5967

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[github-actions]

Codecov Results 📊

✅ 13 passed | Total: 13 | Pass Rate: 100% | Execution Time: 9.58s

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 14966 uncovered lines.

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Generated by Codecov Action