[clang-format] Fix parsing of `operator<() {}` (#75144)

Fixes #74876.

During the parsing of `operator<(Foo&) {}`, there was no handling for
the operator<, so it called `consumeToken()` again, causing the
`AnnotationParser::Scopes` to have one additional left brace each time
it tried to parse it, leaving it unbalanced.
Because of this, in the following code:
```cpp
class Foo {
  void operator<(Foo&) {}
  Foo& f;
};
```
The `&` in the reference member, was being interpreted as
`TT_BinaryOperator` instead of `TT_PointerOrReference`.