chore: normalize test project line endings

[snss10]

Summary

Normalize the repository representation of the two test project files according to .gitattributes.

Problem

Recent dependency updates stored these project files with inconsistent line endings:

• tests/TextRecast.Core.Tests/TextRecast.Core.Tests.csproj
• tests/TextRecast.Infrastructure.Tests/TextRecast.Infrastructure.Tests.csproj

As a result, Git reported both files as modified immediately after a clean checkout, even though their content had not changed.

Changes

• Renormalizes both test project files.
• Preserves the package versions introduced by Dependabot.
• Makes the files follow the repository's configured CRLF working-tree policy.
• Removes the false dirty-working-tree status.

Impact

There are no source-code, dependency-version, project-configuration, or runtime behavior changes.

Validation

• No semantic content differences
• Package versions remain unchanged
• Files follow .gitattributes
• GitHub Actions passes