Update function signatures to use named lifetimes

Refactor `cast_options_from_proto` to accept a named lifetime `'a`,
allowing both protobuf inputs to borrow with `&'a`. Update the
local closure to accept `&'a protobuf::FormatOptions` so that the
returned `FormatOptions` borrows are well-scoped, ensuring better
memory safety and usability.

Author: kosiew

datafusion/proto/src/physical_plan/from_proto.rs

@@ -551,12 +551,12 @@ fn parse_duration_format(
     }
 }
 
-fn cast_options_from_proto(
-    cast_options: Option<&protobuf::PhysicalCastOptions>,
+fn cast_options_from_proto<'a>(
+    cast_options: Option<&'a protobuf::PhysicalCastOptions>,
     safe: bool,
-    format_options: Option<&protobuf::FormatOptions>,
-) -> Result<Option<CastOptions<'_>>> {
-    let parse_format_options = |fo: &protobuf::FormatOptions| {
+    format_options: Option<&'a protobuf::FormatOptions>,
+) -> Result<Option<CastOptions<'a>>> {
+    let parse_format_options = |fo: &'a protobuf::FormatOptions| {
         FormatOptions::new()
             .with_null(fo.null.as_str())
             .with_date_format(fo.date_format.as_deref())