loading: Delete unsafe `normpath` where possible
Unix path semantics allow a symbolic link followed by .. to resolve through the link target, so lexical normalization can change which file a path names. Loading and precompilation were applying normpath directly or through abspath, causing packages in these paths to fail to load.
Add a safe normalization mode that removes harmless dot components while preserving .., use it throughout code loading, and keep depot relocation path spellings intact before falling back to realpath. This preserves symlink semantics and avoids case-folding dependency names on case-insensitive filesystems.
CI failure: https://buildkite.com/julialang/julia-master/builds/52413#019acc0f-d552-4fb6-afd2-7cf7d1266411
Co-authored-by: OpenAI Codex <codex@openai.com>
