Add support for impersonating Firefox ESR 91

As suggested on the Hacker News thread
(https://news.ycombinator.com/item?id=30378562), add support for Firefox
Extended Support Release.

The required changes were adding one more cipher to the
ciphers list and changing the user agent. Apart from that the TLS
fingerprint is identical to Firefox 95 which was already supported.

Dockerfile

@@ -73,6 +73,6 @@ RUN mkdir out && \
     cp ${CURL_VERSION}/src/curl out/curl-impersonate
 
 # Wrapper script
-COPY curl_ff95 out/
+COPY curl_* out/
 
 RUN chmod +x out/*