[red-knot] Port type inference tests to new test framework (#13719)

## Summary

Porting infer tests to new markdown tests framework.

Link to the corresponding issue: #13696

---------

Co-authored-by: Carl Meyer <carl@astral.sh>

crates/red_knot_python_semantic/resources/mdtest/subscript/bytes.md

@@ -0,0 +1,15 @@
+# Bytes subscript
+
+## Simple
+
+```py
+w = b'red' b'knot'
+x = b'hello'
+y = b'world' + b'!'
+z = b'\xff\x00'
+
+reveal_type(w)  # revealed: Literal[b"redknot"]
+reveal_type(x)  # revealed: Literal[b"hello"]
+reveal_type(y)  # revealed: Literal[b"world!"]
+reveal_type(z)  # revealed: Literal[b"\xff\x00"]
+```