Delete legacy limit_path_length hook

Summary:
Step #3 mentioned in D54118734.

Since D55240167 has been pushed, we can now remove the legacy config code.

Reviewed By: andreacampi

Differential Revision: D55313181

fbshipit-source-id: ca7e0b33c054c5cfa838c6ba924333d45ba21683

eden/mononoke/hooks/src/implementations.rs

@@ -86,15 +86,7 @@ pub fn make_file_hook(
                 .build()?,
         )),
         "limit_path_length" => {
-            let hook = if let Some(_json_options) = &params.config.options {
-                limit_path_length::LimitPathLengthHook::new(&params.config)?
-            } else {
-                // TODO(T163510936): delete legacy LimitPathLengthConfig code
-                let legacy_hook_config =
-                    limit_path_length::LimitPathLengthConfig::from_legacy_config(&params.config)?;
-
-                limit_path_length::LimitPathLengthHook::with_config(legacy_hook_config)?
-            };
+            let hook = limit_path_length::LimitPathLengthHook::new(&params.config)?;
             Some(Box::new(hook))
         }
         "no_bad_filenames" => Some(Box::new(no_bad_filenames::NoBadFilenamesHook::new(

eden/mononoke/hooks/src/implementations/limit_path_length.rs

@@ -6,7 +6,6 @@
  */
 
 use anyhow::anyhow;
-use anyhow::Context;
 use anyhow::Error;
 use anyhow::Result;
 use async_trait::async_trait;
@@ -32,20 +31,6 @@ pub struct LimitPathLengthConfig {
     length_limit: usize,
 }
 
-impl LimitPathLengthConfig {
-    // TODO(T163510936): delete legacy LimitPathLengthConfig code
-    pub fn from_legacy_config(config: &HookConfig) -> Result<Self, Error> {
-        let length_limit = config
-            .strings
-            .get("length_limit")
-            .ok_or_else(|| Error::msg("Required config length_limit is missing"))?;
-
-        let length_limit = length_limit.parse().context("While parsing length_limit")?;
-
-        Ok(Self { length_limit })
-    }
-}
-
 /// Hook to block commits changing file paths above a certain length.
 /// This is needed because Mercurial has these limits and we shouldn't allow
 /// commits that can't be synced to mercurial.