Suppress spurious Clippy warnings on v0.6.x

These warnings are no longer triggered in later versions of Clippy,
including all versions after the MSRV that we use on the main branch.

src/lib.rs

@@ -104,6 +104,9 @@
     clippy::unwrap_used,
     clippy::use_debug
 )]
+// Only required on the v0.6.x branch due to behavior of older versions of
+// Clippy which is no longer present on the MSRV we use on the main branch.
+#![allow(clippy::vec_init_then_push)]
 #![deny(
     rustdoc::bare_urls,
     rustdoc::broken_intra_doc_links,
@@ -1352,6 +1355,11 @@ macro_rules! transmute {
             // were to use `core::mem::transmute`, this macro would not work in
             // `std` contexts in which `core` was not manually imported. This is
             // not a problem for 2018 edition crates.
+            //
+            // This `allow` is only required on the v0.6.x branch due to
+            // behavior of older versions of Clippy which is no longer present
+            // on the MSRV we use on the main branch.
+            #[allow(clippy::undocumented_unsafe_blocks)]
             unsafe { $crate::__real_transmute(e) }
         }
     }}