rust: bssl-tls: Drop unused functions

Apparently this function is not useful, because it could be available
after a dereference into TlsConnectionRef.

Signed-off-by: Xiangfei Ding <xfding@google.com>
Change-Id: I2b015d8d3b63a74d17ba3f9d4fdfb7b86a6a6964
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/93507
Presubmit-BoringSSL-Verified: boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Adam Langley <agl@google.com>

rust/bssl-tls/src/connection/lifecycle.rs

diff --git a/rust/bssl-tls/src/connection/lifecycle.rs b/rust/bssl-tls/src/connection/lifecycle.rs
index 142446f..50552ad 100644
--- a/rust/bssl-tls/src/connection/lifecycle.rs
+++ b/rust/bssl-tls/src/connection/lifecycle.rs
@@ -151,21 +151,6 @@
     }
 }
 
-impl<R, M> TlsConnectionInHandshake<'_, R, M>
-where
-    M: HasTlsConnectionMethod,
-{
-    #[allow(unused)] // This method will be used in the following patch to support some async tasks.
-    pub(super) fn get_connection_methods(
-        &mut self,
-    ) -> &mut super::methods::RustConnectionMethods<M> {
-        unsafe {
-            // Safety: the validity of the handle `self.0` is witnessed by `self`.
-            super::get_connection_methods(self.ptr())
-        }
-    }
-}
-
 /// # Handshake
 impl<R, M> TlsConnectionInHandshake<'_, R, M>
 where