remove Allocator parameter from ULID.parse

[lun-4]

if we already know that the length of an ULID is always 26 characters, why would we need the allocator for decoding it?

also fixes zig-ulid for latest zig changes (as ArrayList.toOwnedSlice() can return an error now)

[lun-4]

I didn't notice that ULID has custom struct binding for zig-sqlite through bindField and readField, so https://github.com/vrischmann/zig-sqlite/issues/117 is a dependency for this.

[nektro]

if you know a function is going to do _ = allocator; then you can pass undefined for that parameter if you're using this outside the binding