fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-PSUTIL-483082

requirements.txt

@@ -4,7 +4,7 @@ aiohttp-cors==0.7.0
 aiofiles==0.4.0
 Jinja2>=2.7.3
 sentry-sdk>=0.14.4
-psutil==5.6.6
+psutil==5.6.7
 async-timeout==3.0.1
 distro>=1.3.0
 py-cpuinfo==5.0.0