Bump cryptography in /tools/google-cloud-support-slackbot

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.6.1 to 41.0.3.
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](pyca/cryptography@2.6.1...41.0.3)

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

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

tools/google-cloud-support-slackbot/requirements.txt

@@ -1,4 +1,4 @@
-cryptography==2.6.1
+cryptography==41.0.3
 firebase==3.0.1
 firebase-admin==5.1.0
 Flask==1.1.4