fix(prost-build): MSRV for Context

Author: mzabaluev

prost-build/src/context.rs

@@ -49,20 +49,29 @@ impl<'a> Context<'a> {
 
     /// Returns an iterator over the additional attributes configured
     /// for the named type.
-    pub fn type_attributes(&self, fq_type_name: &str) -> path::Iter<'_, String> {
-        self.config.type_attributes.get(fq_type_name)
+    pub fn type_attributes(&self, fq_type_name: &str) -> impl Iterator<Item = &str> {
+        self.config
+            .type_attributes
+            .get(fq_type_name)
+            .map(|s| s.as_str())
     }
 
     /// Returns an iterator over the additional attributes configured
     /// for the named message.
-    pub fn message_attributes(&self, fq_message_name: &str) -> path::Iter<'_, String> {
-        self.config.message_attributes.get(fq_message_name)
+    pub fn message_attributes(&self, fq_message_name: &str) -> impl Iterator<Item = &str> {
+        self.config
+            .message_attributes
+            .get(fq_message_name)
+            .map(|s| s.as_str())
     }
 
     /// Returns an iterator over the additional attributes configured
     /// for the named enum.
-    pub fn enum_attributes(&self, fq_enum_name: &str) -> path::Iter<'_, String> {
-        self.config.enum_attributes.get(fq_enum_name)
+    pub fn enum_attributes(&self, fq_enum_name: &str) -> impl Iterator<Item = &str> {
+        self.config
+            .enum_attributes
+            .get(fq_enum_name)
+            .map(|s| s.as_str())
     }
 
     /// Returns an iterator over the additional attributes configured