Add chengelog and remove duplicate call to dirname

.changelog/cbeaa629126c4d7bbb6f8b59e76b8835.md

@@ -0,0 +1,4 @@
+---
+type: none
+---
+Fix venv activation not working when using a custom VENV_NAME

script/common.sh

@@ -9,7 +9,7 @@ set -e
 OCTODNS_PATH="$( dirname -- "${SCRIPT_PATH}"; )"
 
 # Change to path OctoDNS base directory
-cd "$( dirname -- "${SCRIPT_PATH}"; )"
+cd "${OCTODNS_PATH}"
 
 # If no venv name is set, set it to "env"
 if [ -z "${VENV_NAME}" ]; then