Switching back to v as prefix, other scripts assume it's presence

z wouldn't work because some scripts in btcpayserver-docker re-append v as prefix to find tag

.circleci/config.yml

@@ -105,15 +105,15 @@ workflows:
             branches:
               ignore: /.*/
             # only act on version tags v1.0.0.88
-            # OR feature tags like zlndseedbackup
+            # OR feature tags like vlndseedbackup
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(z[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
       - arm32v7:
           filters:
             branches:
               ignore: /.*/
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(z[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
       - multiarch:
           requires:
             - amd64
@@ -122,4 +122,4 @@ workflows:
             branches:
               ignore: /.*/
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(z[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/