As discussed in #12820, these old podspecs (0.4.0, 0.3.1, 0.3.0-rc7) pointing to tags that no longer compile with the new architecture (arm64) need to be removed, so they don't generate confusion. All the features from these older versions are available in versions 0.4.1 or 0.4.2.
Merge pull request #12824 from bpoplauschi/remove_problematic_libwebp_versions

Remove libwebp old versions that no are failing to compile