Include radix base prefix in large number representation (#7700)

## Summary

When lexing a number like `0x995DC9BBDF1939FA` that exceeds our small
number representation, we were only storing the portion after the base
(in this case, `995DC9BBDF1939FA`). When using that representation in
code generation, this could lead to invalid syntax, since
`995DC9BBDF1939FA)` on its own is not a valid integer.

This PR modifies the code to store the full span, including the radix
prefix.

See:
https://github.com/astral-sh/ruff/issues/7455#issuecomment-1739802958.

## Test Plan

`cargo test`

crates/ruff_python_parser/src/snapshots/ruff_python_parser__lexer__tests__numbers.snap

@@ -77,8 +77,14 @@ expression: lex_source(source)
         },
         60..63,
     ),
+    (
+        Int {
+            value: 0x995DC9BBDF1939FA,
+        },
+        64..82,
+    ),
     (
         Newline,
-        63..63,
+        82..82,
     ),
 ]