Revert "Temporarily disable some tests."

This reverts commit c57126a.

test/Modules/deRhamComplexes.jl

@@ -46,14 +46,6 @@
   @test d2(A(1//x)*WA[2][4]) == -A(1//x^2)*WA[3][1]
 
   # The graded case
-  # This is disabled for the moment. 
-  # The problem is that `presentation` does not accept zero generators 
-  # for graded modules, but these occur often in this setup. 
-  # We need to keep these generators, because exterior multiplication 
-  # depends on the number and position of the generators. 
-  #
-  # This is an ongoing issue; see #4349.
-  #=
   S, _ = grade(R)
   I = ideal(S, S[4])
   A, pr = quo(S, I)
@@ -67,5 +59,4 @@
   d2 = map(WA, 2)
   @test d2(A(x)*WA[2][4]) == WA[3][1]
   @test "$(WA[2])" == "$(Oscar.is_unicode_allowed() ? "Ω" : "\\Omega")^2($A)"
-  =#
 end