remove unused imports

Author: 9il

source/mir/bignum/decimal.d

@@ -1014,7 +1014,6 @@ struct Decimal(uint maxSize64)
     ///
     version(mir_bignum_test) @safe pure @nogc unittest
     {
-        import std.stdio;
         auto a = Decimal!1("777.7");
         auto b = Decimal!1("777");
         import mir.format;

source/mir/ndslice/topology.d

@@ -1074,7 +1074,6 @@ Slice!(Iterator, 1, Universal)
     //->
     // | 1 2 |
     static immutable c = [1, 2];
-    import std.stdio;
     assert(iota(2, 2).antidiagonal == c);
 }
 
@@ -1969,7 +1968,6 @@ auto linspace(T, size_t N)(size_t[N] lengths, T[2][N] intervals...)
 version(mir_ndslice_test) unittest
 {
     import mir.ndslice;
-    // import std.stdio: writefln;
 
     enum fmt = "%(%(%.2f %)\n%)\n";
 
@@ -4321,7 +4319,6 @@ version(mir_ndslice_test) unittest
     // 4 5  6  7
     // 8 9 10 11
     auto s = iota(3, 4);
-    import std.stdio;
     assert(iota(3, 4).byDim!0.diff == [
         [4, 4, 4, 4],
         [4, 4, 4, 4]]);

source/mir/rc/array.d

@@ -799,8 +799,6 @@ unittest
 version(mir_test)
 @safe unittest
 {
-    import core.stdc.stdio;
-
     struct S
     {
         uint s;

source/mir/string_map.d

@@ -683,7 +683,6 @@ struct StringMap(T, U = uint)
     +/
     ref T require()(string key, lazy T value = T.init)
     {
-        import std.stdio;
         size_t index;
         if (_expect(!implementation, false))
         {