fix(tvix/eval/versions): dash is a divider, not underscore

https: //github.com/NixOS/nix/blob/cd35bbbeef72375873e396b9ffed14a4638693a8/src/libstore/names.cc#L63
Change-Id: I1d5aba6060d11778f3b79089f4b27ef8849e4d37
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6709
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

tvix/eval/src/builtins/versions.rs

@@ -57,7 +57,7 @@ impl<'a> Iterator for VersionPartsIter<'a> {
         let (pos, char) = char.unwrap();
         match char {
             // Divider encountered
-            '.' | '_' => {
+            '.' | '-' => {
                 let cached_part = std::mem::replace(&mut self.cached_part, InternalPart::Break);
                 match cached_part {
                     InternalPart::Number { range } => {