Remove edit action markers literals from source (#27778)

Edit action markers look like git conflicts and can trip up tooling used
to resolve git conflicts. This PR creates them programmatically so that
they don't appear in source code.

Release Notes:

- N/A

crates/assistant_tools/src/find_replace_file_tool.rs

@@ -65,7 +65,7 @@ pub struct FindReplaceFileToolInput {
     /// <example>
     /// If a file contains this code:
     ///
-    /// ```rust
+    /// ```ignore
     /// fn check_user_permissions(user_id: &str) -> Result<bool> {
     ///     // Check if user exists first
     ///     let user = database.find_user(user_id)?;
@@ -83,7 +83,7 @@ pub struct FindReplaceFileToolInput {
     /// Your find string should include at least 3 lines of context before and after the part
     /// you want to change:
     ///
-    /// ```
+    /// ```ignore
     /// fn check_user_permissions(user_id: &str) -> Result<bool> {
     ///     // Check if user exists first
     ///     let user = database.find_user(user_id)?;
@@ -100,7 +100,7 @@ pub struct FindReplaceFileToolInput {
     ///
     /// And your replace string might look like:
     ///
-    /// ```
+    /// ```ignore
     /// fn check_user_permissions(user_id: &str) -> Result<bool> {
     ///     // Check if user exists first
     ///     let user = database.find_user(user_id)?;