Bump waitress from 2.0.0 to 2.1.1 in /backend

Bumps [waitress](https://github.com/Pylons/waitress) from 2.0.0 to 2.1.1.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/master/CHANGES.txt)
- [Commits](https://github.com/Pylons/waitress/compare/v2.0.0...v2.1.1)

---
updated-dependencies:
- dependency-name: waitress
  dependency-type: direct:production
...

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

backend/poetry.lock

@@ -1267,11 +1267,11 @@ python-versions = ">=3.6"
 
 [[package]]
 name = "waitress"
-version = "2.0.0"
+version = "2.1.1"
 description = "Waitress WSGI server"
 category = "main"
 optional = false
-python-versions = ">=3.6.0"
+python-versions = ">=3.7.0"
 
 [package.extras]
 docs = ["Sphinx (>=1.8.1)", "docutils", "pylons-sphinx-themes (>=1.0.9)"]
@@ -1314,7 +1314,7 @@ postgresql = []
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.8"
-content-hash = "ba374bd631f54e82e0eaaa41cd38d6b6e71f69d3e5202a5c46575667b12f2b10"
+content-hash = "d7f1f44c2c0fe6bf788aa5bdba0ff238b9d77610a7cda0528e5ba91ca43cba62"
 
 [metadata.files]
 amqp = [
@@ -2186,8 +2186,8 @@ vine = [
     {file = "vine-5.0.0.tar.gz", hash = "sha256:7d3b1624a953da82ef63462013bbd271d3eb75751489f9807598e8f340bd637e"},
 ]
 waitress = [
-    {file = "waitress-2.0.0-py3-none-any.whl", hash = "sha256:29af5a53e9fb4e158f525367678b50053808ca6c21ba585754c77d790008c746"},
-    {file = "waitress-2.0.0.tar.gz", hash = "sha256:69e1f242c7f80273490d3403c3976f3ac3b26e289856936d1f620ed48f321897"},
+    {file = "waitress-2.1.1-py3-none-any.whl", hash = "sha256:c549f5b2b4afd44d9d97d7cec79f3ef581e25d832827f415dc175327af674aa8"},
+    {file = "waitress-2.1.1.tar.gz", hash = "sha256:e2e60576cf14a1539da79f7b7ee1e79a71e64f366a0b47db54a15e971f57bb16"},
 ]
 watchdog = [
     {file = "watchdog-2.1.6-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:9693f35162dc6208d10b10ddf0458cc09ad70c30ba689d9206e02cd836ce28a3"},