CI taskgraph failing due to Python 2.7 running Python 3 code #5070
Description
Describe the bug
In #5069 (comment), the decision task is running Python 2.7 against our Python 3-only code.
Expected behavior
Python 3 should be used to run the decision task
Taskcluster version
v44.2.2 (although Python 2.7 wasn't dropped until v44.4.0
Additional context
We're using 2-year old versions of the taskgraph code and the taskgraph/decision Docker image. An update might fix.