Preserve comments on version bump (#16141)

## Summary
Fixes [1633](https://github.com/astral-sh/uv/issues/16133). Preserves
comments preceding "version = ..." line when uv version --bump is ran

## Test Plan
Added IT test

---------

Co-authored-by: konsti <konstin@mailbox.org>

crates/uv-workspace/src/pyproject_mut.rs

@@ -1141,10 +1141,18 @@ impl PyProjectTomlMut {
             .get_mut("project")
             .and_then(Item::as_table_mut)
             .ok_or(Error::MalformedWorkspace)?;
-        project.insert(
+
-            "version",
+        if let Some(existing) = project.get_mut("version") {
-            Item::Value(Value::String(Formatted::new(version.to_string()))),
+            if let Some(value) = existing.as_value_mut() {
-        );
+                let mut formatted = Value::from(version.to_string());
+                *formatted.decor_mut() = value.decor().clone();
+                *value = formatted;
+            } else {
+                *existing = Item::Value(Value::from(version.to_string()));
+            }
+        } else {
+            project.insert("version", Item::Value(Value::from(version.to_string())));
+        }
 
         Ok(())
     }

crates/uv/tests/it/version.rs

@@ -289,6 +289,50 @@ requires-python = ">=3.12"
     Ok(())
 }
 
+/// Preserve comments immediately preceding the version when bumping
+#[test]
+fn version_bump_preserves_preceding_comments() -> Result<()> {
+    let context: TestContext = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "hello-world"
+        # pre-1: stays above version
+        # pre-2: stays below pre-1
+        version = "0.1.0" # eol: stays on same line
+        # after-version: remains after version
+        description = "Add your description here"
+        "#,
+    )?;
+
+    // Bump patch version
+    context
+        .version()
+        .arg("--bump")
+        .arg("patch")
+        .assert()
+        .success();
+
+    // Ensure comments are preserved around the version entry
+    let pyproject = fs_err::read_to_string(&pyproject_toml)?;
+    assert_snapshot!(
+        pyproject,
+        @r#"
+        [project]
+        name = "hello-world"
+        # pre-1: stays above version
+        # pre-2: stays below pre-1
+        version = "0.1.1" # eol: stays on same line
+        # after-version: remains after version
+        description = "Add your description here"
+        "#
+    );
+
+    Ok(())
+}
+
 // Bump minor version
 #[test]
 fn version_bump_minor() -> Result<()> {