This commit adds tests for uncovered error paths and edge cases in
pkg/gitinterface, and refactors existing tests for clarity:
- Add error path tests for CheckAndSetReference, SetReference,
DeleteReference, RefSpec, CanSign, VerifySignature,
TagUsingSpecificKey, GetAllFilesInTree, EnsureIsCommit,
GetTagTarget, ensureIsTag, and other helpers
- Inline error-case test functions into parent tests using t.Run
subtests for better organization
- Extract inline byte slices into named variables for readability
- Simplify temp directory usage where subdirectories are unnecessary
- Remove redundant parser-level error tests
- Format files with gofmt
Signed-off-by: dawgdevv <nraj02415@gmail.com>
