fix: address clippy warnings in diagnostics commands

- Add #[allow(dead_code)] attributes for methods used via trait impl
- Add #[allow(dead_code)] for helper functions
- Ensure all clippy checks pass with -D warnings flag

Author: joshrotenberg

crates/redisctl/src/commands/enterprise/diagnostics.rs

@@ -54,6 +54,7 @@ pub enum DiagnosticsCommands {
 }
 
 impl DiagnosticsCommands {
+    #[allow(dead_code)]
     pub async fn execute(
         &self,
         conn_mgr: &ConnectionManager,
@@ -201,6 +202,7 @@ impl DiagnosticsCommands {
     }
 }
 
+#[allow(dead_code)]
 pub async fn handle_diagnostics_command(
     conn_mgr: &ConnectionManager,
     profile_name: Option<&str>,
@@ -214,6 +216,7 @@ pub async fn handle_diagnostics_command(
 }
 
 // Helper functions
+#[allow(dead_code)]
 fn parse_comma_separated(input: &Option<String>) -> Option<Vec<String>> {
     input.as_ref().map(|s| {
         s.split(',')
@@ -223,6 +226,7 @@ fn parse_comma_separated(input: &Option<String>) -> Option<Vec<String>> {
     })
 }
 
+#[allow(dead_code)]
 fn parse_comma_separated_u32(input: &Option<String>) -> Option<Vec<u32>> {
     input.as_ref().and_then(|s| {
         let values: Result<Vec<u32>, _> = s