fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-DEBIAN11-DPKG-2847942
- https://snyk.io/vuln/SNYK-DEBIAN11-OPENSSL-2807596
- https://snyk.io/vuln/SNYK-DEBIAN11-PCRE2-2808697
- https://snyk.io/vuln/SNYK-DEBIAN11-PCRE2-2808704
- https://snyk.io/vuln/SNYK-DEBIAN11-UTILLINUX-2401081

Dockerfile

@@ -1,5 +1,5 @@
 # Build image
-FROM debian:bullseye AS tor
+FROM debian:11 AS tor
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -qq && apt-get install -y apt-transport-https wget gnupg
 RUN echo "deb [signed-by=/usr/share/keyrings/tor-archive-keyring.gpg] https://deb.torproject.org/torproject.org bullseye main" >/etc/apt/sources.list.d/tor.list