ruff_db: move ParseDiagnostic to old submodule too

This should have been with the previous two commits, but I missed it.

crates/ruff_db/src/diagnostic/mod.rs

@@ -1,14 +1,12 @@
-use std::borrow::Cow;
 use std::fmt::Formatter;
 
 use thiserror::Error;
 
 use ruff_annotate_snippets::Level as AnnotateLevel;
-use ruff_python_parser::ParseError;
 use ruff_text_size::TextRange;
 
 pub use crate::diagnostic::old::{
-    OldDiagnosticTrait, OldDisplayDiagnostic, OldSecondaryDiagnosticMessage,
+    OldDiagnosticTrait, OldDisplayDiagnostic, OldParseDiagnostic, OldSecondaryDiagnosticMessage,
 };
 use crate::files::File;
 
@@ -245,33 +243,3 @@ impl DisplayDiagnosticConfig {
         DisplayDiagnosticConfig { color: yes }
     }
 }
-
-#[derive(Debug)]
-pub struct OldParseDiagnostic {
-    file: File,
-    error: ParseError,
-}
-
-impl OldParseDiagnostic {
-    pub fn new(file: File, error: ParseError) -> Self {
-        Self { file, error }
-    }
-}
-
-impl OldDiagnosticTrait for OldParseDiagnostic {
-    fn id(&self) -> DiagnosticId {
-        DiagnosticId::InvalidSyntax
-    }
-
-    fn message(&self) -> Cow<str> {
-        self.error.error.to_string().into()
-    }
-
-    fn span(&self) -> Option<Span> {
-        Some(Span::from(self.file).with_range(self.error.location))
-    }
-
-    fn severity(&self) -> Severity {
-        Severity::Error
-    }
-}

crates/ruff_db/src/diagnostic/old.rs

@@ -4,11 +4,13 @@ use ruff_annotate_snippets::{
     Annotation as AnnotateAnnotation, Level as AnnotateLevel, Message as AnnotateMessage,
     Renderer as AnnotateRenderer, Snippet as AnnotateSnippet,
 };
+use ruff_python_parser::ParseError;
 use ruff_source_file::{OneIndexed, SourceCode};
 use ruff_text_size::TextRange;
 
 use crate::{
     diagnostic::{DiagnosticId, DisplayDiagnosticConfig, Severity, Span},
+    files::File,
     source::{line_index, source_text},
     Db,
 };
@@ -342,3 +344,33 @@ impl OldDiagnosticTrait for std::sync::Arc<dyn OldDiagnosticTrait> {
         (**self).severity()
     }
 }
+
+#[derive(Debug)]
+pub struct OldParseDiagnostic {
+    file: File,
+    error: ParseError,
+}
+
+impl OldParseDiagnostic {
+    pub fn new(file: File, error: ParseError) -> Self {
+        Self { file, error }
+    }
+}
+
+impl OldDiagnosticTrait for OldParseDiagnostic {
+    fn id(&self) -> DiagnosticId {
+        DiagnosticId::InvalidSyntax
+    }
+
+    fn message(&self) -> Cow<str> {
+        self.error.error.to_string().into()
+    }
+
+    fn span(&self) -> Option<Span> {
+        Some(Span::from(self.file).with_range(self.error.location))
+    }
+
+    fn severity(&self) -> Severity {
+        Severity::Error
+    }
+}