Delete ArrayVecCopy::new_const since it doesn't work on Rust 1.51

```
error[E0723]: trait bounds other than `Sized` on const fn parameters are unstable
  --> src/arrayvec_copy.rs:59:6
   |
59 | impl<T: Copy, const CAP: usize> ArrayVecCopy<T, CAP> {
   |      ^
   |
   = note: see issue #57563 <rust-lang/rust#57563> for more information
   = help: add `#![feature(const_fn)]` to the crate attributes to enable
```

src/arrayvec_copy.patch

@@ -1,5 +1,5 @@
 diff --git a/src/arrayvec_copy_generated.rs b/src/arrayvec_copy.rs
-index b12aa9e..5597af9 100644
+index b12aa9e..8e4c3a9 100644
 --- a/src/arrayvec_copy_generated.rs
 +++ b/src/arrayvec_copy.rs
 @@ -27,6 +27,9 @@ use crate::utils::MakeMaybeUninit;
@@ -27,7 +27,28 @@ index b12aa9e..5597af9 100644
  macro_rules! panic_oob {
      ($method_name:expr, $index:expr, $len:expr) => {
          panic!(concat!("ArrayVecCopy::", $method_name, ": index {} is out of bounds in vector of length {}"),
-@@ -964,21 +959,6 @@ impl<T: Copy, const CAP: usize> DoubleEndedIterator for IntoIter<T, CAP> {
+@@ -87,20 +82,6 @@ impl<T: Copy, const CAP: usize> ArrayVecCopy<T, CAP> {
+         }
+     }
+
+-    /// Create a new empty `ArrayVecCopy` (const fn).
+-    ///
+-    /// The maximum capacity is given by the generic parameter `CAP`.
+-    ///
+-    /// ```
+-    /// use arrayvec::ArrayVecCopy;
+-    ///
+-    /// static ARRAY: ArrayVecCopy<u8, 1024> = ArrayVecCopy::new_const();
+-    /// ```
+-    pub const fn new_const() -> ArrayVecCopy<T, CAP> {
+-        assert_capacity_limit_const!(CAP);
+-        ArrayVecCopy { xs: MakeMaybeUninit::ARRAY, len: 0 }
+-    }
+-
+     /// Return the number of elements in the `ArrayVecCopy`.
+     ///
+     /// ```
+@@ -964,21 +945,6 @@ impl<T: Copy, const CAP: usize> DoubleEndedIterator for IntoIter<T, CAP> {
 
  impl<T: Copy, const CAP: usize> ExactSizeIterator for IntoIter<T, CAP> { }
 

src/arrayvec_copy.rs

@@ -82,20 +82,6 @@ impl<T: Copy, const CAP: usize> ArrayVecCopy<T, CAP> {
         }
     }
 
-    /// Create a new empty `ArrayVecCopy` (const fn).
-    ///
-    /// The maximum capacity is given by the generic parameter `CAP`.
-    ///
-    /// ```
-    /// use arrayvec::ArrayVecCopy;
-    ///
-    /// static ARRAY: ArrayVecCopy<u8, 1024> = ArrayVecCopy::new_const();
-    /// ```
-    pub const fn new_const() -> ArrayVecCopy<T, CAP> {
-        assert_capacity_limit_const!(CAP);
-        ArrayVecCopy { xs: MakeMaybeUninit::ARRAY, len: 0 }
-    }
-
     /// Return the number of elements in the `ArrayVecCopy`.
     ///
     /// ```