Bump waitress from 1.3.1 to 1.4.0

Bumps [waitress](https://github.com/Pylons/waitress) from 1.3.1 to 1.4.0.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/master/CHANGES.txt)
- [Commits](Pylons/waitress@v1.3.1...v1.4.0)

Signed-off-by: dependabot[bot] <support@github.com>

constraints.txt

@@ -36,7 +36,7 @@ roman==3.2
 shutilwhich==1.1.0
 six==1.13.0
 transaction==2.4.0
-waitress==1.3.1
+waitress==1.4.0
 z3c.pt==3.2.0
 zExceptions==4.1
 zc.lockfile==2.0

requirements-full.txt

@@ -37,7 +37,7 @@ roman==3.2
 shutilwhich==1.1.0
 six==1.13.0
 transaction==2.4.0
-waitress==1.3.1
+waitress==1.4.0
 z3c.pt==3.2.0
 zExceptions==4.1
 zc.lockfile==2.0