Revert "Implement ToStringView for Char (#2889)"

This reverts commit 279a9dc.

Author: hackwaly

array/array_test.mbt

@@ -299,13 +299,3 @@ test "panic fill with invalid end" {
   let arr = [1, 2, 3, 4, 5]
   arr.fill(0, start=2, end=10)
 }
-
-///|
-test "Array::join with Char" {
-  let chars : Array[Char] = ['h', 'e', 'l', 'l', 'o']
-  let result = chars.join("")
-  inspect(result, content="hello")
-  let chars2 : Array[Char] = ['a', 'b', 'c']
-  let result2 = chars2.join(", ")
-  inspect(result2, content="a, b, c")
-}

string/pkg.generated.mbti

@@ -151,7 +151,6 @@ impl ToJson for StringView
 pub trait ToStringView {
   to_string_view(Self) -> StringView
 }
-impl ToStringView for Char
 impl ToStringView for String
 impl ToStringView for StringView
 

string/string_like.mbt

@@ -26,9 +26,3 @@ pub impl ToStringView for String with to_string_view(self) -> StringView {
 pub impl ToStringView for StringView with to_string_view(self) -> StringView {
   self
 }
-
-///|
-/// Implements ToStringView for Char, enabling operations like Array::join on Array[Char]
-pub impl ToStringView for Char with to_string_view(self) -> StringView {
-  [self]
-}