DOC: fix pandas-coverage link (pandas-dev#53971)

fix pandas-coverage link

Author: MarcoGorelli

doc/source/development/contributing_codebase.rst

@@ -764,7 +764,7 @@ install pandas) by typing::
     your installation is probably fine and you can start contributing!
 
 Often it is worth running only a subset of tests first around your changes before running the
-entire suite (tip: you can use the [pandas-coverage app](https://pandas-coverage.herokuapp.com/))
+entire suite (tip: you can use the [pandas-coverage app](https://pandas-coverage-12d2130077bc.herokuapp.com/))
 to find out which tests hit the lines of code you've modified, and then run only those).
 
 The easiest way to do this is with::