Fix #3607 (#3619)

Fixes #3607.

In the fusion reported in #3607, there's a proposed fusion segment as
shown below:

```
**Segmenter** Considering fusion:
T14_g_double[iS27{2}, rS28{24000}](Avg),
T15_l_double[iS29{2}, rS30{24000}](Var),
T16_l_nvfuser_index_t[iS31{2}, rS32{24000}](Count)
 = Welford ( T2_g_double[iS3{2}, iS4{24000}](Avg),
  allreduce = false )
d59 = (double)(24000);
d61 = double(1) * d59;
d65 = (double)(0);
d67 = d61 - d65;
d69 = (double)(0);
b71 = d67 >= d69;
d73 = (double)(0);
d75 = where(b71, d67, d73);
d80 = reciprocal(d75);
T17_l_double[iS33{2}]
   = T15_l_double[iS29{2}, rS30{24000}]
   * d80;
T23_l_double[iS44{2}, bS45{1}]
   = broadcast( T17_l_double[iS33{2}] )
T25_l_double[iS48{2}, bS49{1}]
   = T23_l_double[iS44{2}, bS45{1}]
   + double(1.0000000000000001e-05);
T26_g_double[iS50{2}, bS51{1}]
   = rsqrt(T25_l_double[iS48{2}, bS49{1}]);
T27_l_double[iS52{2}, bS53{1}]
   = Set( T26_g_double[iS50{2}, bS51{1}], cache_op=Streaming )
T28_g_double[iS54{2}, bS55{1 ex 24000}] = expand( T27_l_double[iS52{2}, bS53{1}], {2, 24000} )
T32_g_double[iS62{2}, iS63{24000}]
   = T28_g_double[iS54{2}, bS55{1 ex 24000}]
   * T13_g_double[iS25{2}, iS26{24000}];
T37_l_double[iS72{2}, iS73{24000}]
   = -T32_g_double[iS62{2}, iS63{24000}];
T38_g_double[iS74{2}, rS75{24000}]
   = reduction( T37_l_double[iS72{2}, iS73{24000}], op = add, initial value = double(0), allreduce = false )
```

When `canScheduleCompileTime` of the transpose scheduler is called,
`FindAllMappedDims` is used with `T32` as the reference. Since its
innermost dimension is not connected with `T15` due to the reduction,
`propagateSibling` hits the assertion at
https://github.com/NVIDIA/Fuser/blob/main/csrc/scheduler/utils.cpp#L1476.

This PR avoids the assertion by checking the existence of reduction
first. We may also want to remove the assertion.

csrc/scheduler/transpose.cpp

@@ -68,12 +68,6 @@ bool TransposeScheduler::canScheduleCompileTime(Fusion* fusion) {
     }
   }
 
-  if (!hasAtLeastTwoValidGroups(fusion)) {
-    scheduler_debug_utils::canScheduleRejectReason(
-        schedulerType(), "cannot find two mismatching inner most dimensions");
-    return false;
-  }
-
   if (ir_utils::hasAnyReductionOps(fusion)) {
     scheduler_debug_utils::canScheduleRejectReason(
         schedulerType(), "no support for reduction ops");
@@ -87,6 +81,12 @@ bool TransposeScheduler::canScheduleCompileTime(Fusion* fusion) {
     return false;
   }
 
+  if (!hasAtLeastTwoValidGroups(fusion)) {
+    scheduler_debug_utils::canScheduleRejectReason(
+        schedulerType(), "cannot find two mismatching inner most dimensions");
+    return false;
+  }
+
   return true;
 }