Change tuple() to () for slightly improved performance in trt_compiler.py (#8749)

### Description
See also #8747 and #8748 

### Types of changes
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Non-breaking change (fix or new feature that would not break
existing functionality).
- [ ] Breaking change (fix or new feature that would cause existing
functionality to change).
- [ ] New tests added to cover the changes.
- [ ] Integration tests passed locally by running `./runtests.sh -f -u
--net --coverage`.
- [ ] Quick tests passed locally by running `./runtests.sh --quick
--unittests --disttests`.
- [ ] In-line docstrings updated.
- [ ] Documentation updated, tested `make html` command in the `docs/`
folder.

---------

Signed-off-by: Benedikt Johannes <benedikt.johannes.hofer@gmail.com>
Co-authored-by: Eric Kerfoot <17726042+ericspod@users.noreply.github.com>

Author: benediktjohannes

monai/networks/trt_compiler.py

@@ -261,10 +261,10 @@ def parse_groups(
        Tuple of Union[torch.Tensor, List[torch.Tensor]], according to the grouping in output_lists
 
     """
-    groups: tuple[torch.Tensor | list[torch.Tensor], ...] = tuple()
+    groups: tuple[torch.Tensor | list[torch.Tensor], ...] = ()
     cur = 0
-    for l in range(len(output_lists)):
-        gl = output_lists[l]
+    for idx in range(len(output_lists)):
+        gl = output_lists[idx]
         assert len(gl) == 0 or len(gl) == 1
         if len(gl) == 0 or gl[0] == 0:
             groups = (*groups, ret[cur])
@@ -273,9 +273,9 @@ def parse_groups(
             groups = (*groups, ret[cur : cur + gl[0]])
             cur = cur + gl[0]
         elif gl[0] == -1:
-            rev_groups: tuple[torch.Tensor | list[torch.Tensor], ...] = tuple()
+            rev_groups: tuple[torch.Tensor | list[torch.Tensor], ...] = ()
             rcur = len(ret)
-            for rl in range(len(output_lists) - 1, l, -1):
+            for rl in range(len(output_lists) - 1, idx, -1):
                 rgl = output_lists[rl]
                 assert len(rgl) == 0 or len(rgl) == 1
                 if len(rgl) == 0 or rgl[0] == 0: