neovim: bump version and cleanup

[albestro]

Changes:

• add and document constraint about tree-sitter@0.26 due to api changes
• add some missing upper bounds/type for "repeated" depends_on
• group dependencies that were duplicated after versions deprecation
• drop wrong upper bound for libluv (it was not applied anyway in most cases, because of the missing upper bounds in other declarations of the same dependency)