Update .lycheeignore (#3159)

Adding a link from a tutorial (intermediate_source/tensorboard_tutorial.rst) to the ignore list as it is picked up by lychee but is only possible locally when running tutorial.

Co-authored-by: Svetlana Karslioglu <svekars@meta.com>

Author: sekyondaMeta

.lycheeignore

@@ -9,3 +9,6 @@ file:\/\/\/.*
 
 # Ignore colab link in the setting of conf.py
 https://pytorch.org/tutorials/beginner/colab/n
+
+# Ignore local host link from intermediate_source/tensorboard_tutorial.rst
+http://localhost:6006