Merge branch 'genofire-master-patch-22893' into 'master'

fix tls/https connections: take CA certs from builder

See merge request silkeh/alertmanager_matrix!4

(cherry picked from commit 46ccb1c06dd49c7eadf0001db411a9d91229c12c)

191d419f fix tls/https connections: take CA certs from builder

Dockerfile

@@ -6,5 +6,6 @@ COPY [".", "/build"]
 RUN cd /build && CGO_ENABLED=0 go build -ldflags="-s -w" ./cmd/alertmanager_matrix
 
 FROM scratch
+COPY --from=build ["/etc/ssl/cert.pem", "/etc/ssl/certs/ca-certificates.crt"] 
 COPY --from=build ["/build/alertmanager_matrix", "/usr/local/bin/"]
 ENTRYPOINT ["/usr/local/bin/alertmanager_matrix"]