Fixes#16185
# Description
Stepped range literals where `..=` precedes the second value no longer
cause a parser panic:
```diff
random int 1..=3..5
-Error: x Main thread panicked.
- |-> at crates/nu-protocol/src/engine/state_working_set.rs:400:48
- `-> slice index starts at 8 but ends at 7
+Error: nu::parser::parse_mismatch
+
+ × Parse mismatch during operation.
+ ╭─[entry #1:1:15]
+ 1 │ random int 1..=3..5
+ · ─┬
+ · ╰── expected number
```
89c0e325fa