Revert "add 'ᵀ postfix operator for transpose (#38062)" (#40075)

This reverts commit 665279a.

(cherry picked from commit 7838e09)

Author: KristofferC

NEWS.md

@@ -114,7 +114,6 @@ New library features
   inserting or consuming the first dimension depending on the ratio of `sizeof(T)` and `sizeof(S)`.
 * New `append!(vector, collections...)` and `prepend!(vector, collections...)` methods accept multiple
   collections to be appended or prepended ([#36227]).
-* The postfix operator `'ᵀ` can now be used as an alias for `transpose` ([#38062]).
 * `keys(io::IO)` has been added, which returns all keys of `io` if `io` is an `IOContext` and an empty
   `Base.KeySet` otherwise ([#37753]).
 * `count` now accepts an optional `init` argument to control the accumulation type ([#37461]).

base/exports.jl

@@ -467,7 +467,6 @@ export
 # linear algebra
     var"'", # to enable syntax a' for adjoint
     adjoint,
-    var"'ᵀ",
     transpose,
     kron,
     kron!,

base/operators.jl

@@ -567,7 +567,6 @@ end
 function kron! end
 
 const var"'" = adjoint
-const var"'ᵀ" = transpose
 
 """
     \\(x, y)

stdlib/LinearAlgebra/src/adjtrans.jl

@@ -136,7 +136,6 @@ julia> x'x
 adjoint(A::AbstractVecOrMat) = Adjoint(A)
 
 """
-    A'ᵀ
     transpose(A)
 
 Lazy transpose. Mutating the returned object should appropriately mutate `A`. Often,
@@ -146,9 +145,6 @@ that this operation is recursive.
 This operation is intended for linear algebra usage - for general data manipulation see
 [`permutedims`](@ref Base.permutedims), which is non-recursive.
 
-!!! compat "Julia 1.6"
-    The postfix operator `'ᵀ` requires Julia 1.6.
-
 # Examples
 ```jldoctest
 julia> A = [3+2im 9+2im; 8+7im  4+6im]
@@ -160,14 +156,6 @@ julia> transpose(A)
 2×2 transpose(::Matrix{Complex{Int64}}) with eltype Complex{Int64}:
  3+2im  8+7im
  9+2im  4+6im
-
-julia> x = [3, 4im]
-2-element Vector{Complex{Int64}}:
- 3 + 0im
- 0 + 4im
-
-julia> x'ᵀx
--7 + 0im
 ```
 """
 transpose(A::AbstractVecOrMat) = Transpose(A)

test/operators.jl

@@ -253,7 +253,4 @@ end
     @test ∋(0)(-2:2)
 end
 
-a = rand(3, 3)
-@test transpose(a) === a'ᵀ
-
 @test [Base.afoldl(+, 1:i...) for i = 1:40] == [i * (i + 1) ÷ 2 for i = 1:40]