Implement AnyNode/AnyNodeRef for FStringFormatSpec (#9836)

## Summary

This PR adds the `AnyNode` and `AnyNodeRef` implementation for
`FStringFormatSpec` node which will be required in the f-string
formatting.

The main usage for this is so that we can pass in the node directly to
`suppressed_node` in case debug expression is used to format is as
verbatim text.

crates/ruff_python_formatter/src/range.rs

@@ -666,6 +666,7 @@ impl Format<PyFormatContext<'_>> for FormatEnclosingNode<'_> {
             | AnyNodeRef::ExprCall(_)
             | AnyNodeRef::FStringExpressionElement(_)
             | AnyNodeRef::FStringLiteralElement(_)
+            | AnyNodeRef::FStringFormatSpec(_)
             | AnyNodeRef::ExprFString(_)
             | AnyNodeRef::ExprStringLiteral(_)
             | AnyNodeRef::ExprBytesLiteral(_)