Bump waitress from 2.1.1 to 2.1.2 in /backend

Bumps [waitress](https://github.com/Pylons/waitress) from 2.1.1 to 2.1.2.
- [Release notes](https://github.com/Pylons/waitress/releases)
- [Changelog](https://github.com/Pylons/waitress/blob/v2.1.2/CHANGES.txt)
- [Commits](https://github.com/Pylons/waitress/compare/v2.1.1...v2.1.2)

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

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

backend/poetry.lock

@@ -1460,7 +1460,7 @@ python-versions = ">=3.6"
 
 [[package]]
 name = "waitress"
-version = "2.1.1"
+version = "2.1.2"
 description = "Waitress WSGI server"
 category = "main"
 optional = false
@@ -2545,8 +2545,8 @@ vine = [
     {file = "vine-5.0.0.tar.gz", hash = "sha256:7d3b1624a953da82ef63462013bbd271d3eb75751489f9807598e8f340bd637e"},
 ]
 waitress = [
-    {file = "waitress-2.1.1-py3-none-any.whl", hash = "sha256:c549f5b2b4afd44d9d97d7cec79f3ef581e25d832827f415dc175327af674aa8"},
-    {file = "waitress-2.1.1.tar.gz", hash = "sha256:e2e60576cf14a1539da79f7b7ee1e79a71e64f366a0b47db54a15e971f57bb16"},
+    {file = "waitress-2.1.2-py3-none-any.whl", hash = "sha256:7500c9625927c8ec60f54377d590f67b30c8e70ef4b8894214ac6e4cad233d2a"},
+    {file = "waitress-2.1.2.tar.gz", hash = "sha256:780a4082c5fbc0fde6a2fcfe5e26e6efc1e8f425730863c04085769781f51eba"},
 ]
 watchdog = [
     {file = "watchdog-2.1.6-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:9693f35162dc6208d10b10ddf0458cc09ad70c30ba689d9206e02cd836ce28a3"},