fix: add zlib to Windows build

[patrick-stephens]

Resolves #302 by ensuring we provide zlib during the build for Windows.

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Summary by cubic

Fixes Windows builds by installing zlib via vcpkg, linking ZLIB::ZLIB, and passing the vcpkg toolchain/triplet to CMake; also installs libgit2 via vcpkg. Reverts zstd detection to the 4.1.x pkg-config flow; resolves #302.

• Refactors
  • Windows workflow cleanup: split configure/build steps, print build logs for debugging, and remove build package upload.

^{Written for commit 3eaaf89. Summary will update on new commits. Review in cubic}

[patrick-stephens]

/build windows

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[github-actions]

Build results for /build on PR #307:

• Windows: ❌ (failure) — Job logs

[patrick-stephens]

Unfortunately the PR build comment runner invokes the workflow from the default branch rather than the updated one.

[coveralls]

Coverage Report for CI Build 26290622149

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage decreased (-0.001%) to 58.243%

Details

• Coverage decreased (-0.001%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 5 coverage regressions across 2 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

5 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
src/flb_http_client.c	3	43.88%
src/flb_storage.c	2	73.58%

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Coverage Stats

Relevant Lines:	160303
Covered Lines:	94454
Line Coverage:	58.92%
Relevant Branches:	35307
Covered Branches:	19476
Branch Coverage:	55.16%
Branches in Coverage %:	Yes
Coverage Strength:	5822.52 hits per line

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💛 - Coveralls