formula: cxong/tinydir

[MeteorsLiu]

Summary:

• Add the Conan Center tinydir 1.2.4–1.2.6 header-only range.
• Install the header and license, publish relocatable pkg-config metadata, and verify the C consumer.

Validation:

• llar test for 1.2.4, 1.2.5, and 1.2.6 on linux/amd64.
• llar test for 1.2.6 on linux/arm64, darwin/amd64, and darwin/arm64.
• Cache-hit consumer test and relocated pkg-config lookup.

Closes #264

[fennoai]

Review conclusion

Reviewed the complete fixed diff for the cxong/tinydir Formula, including version selection, header and license installation, relocatable pkg-config metadata, and the cache-safe C consumer test. I found no actionable correctness, compatibility, security, or maintainability issues introduced by this PR. git diff --check passes. The repository CI status collected for this head was pending/cancelled, and llar is not installed in the review workspace, so the claimed cross-platform llar test matrix could not be independently rerun here.