update python to 3.9

Dockerfile

-FROM python:3.7-alpine
+FROM python:3.9-alpine
 
 RUN apk add --update gcc libc-dev linux-headers curl && rm -rf /var/cache/apk/*
 

poetry.lock

@@ -143,8 +143,8 @@ socks = ["PySocks (>=1.5.6,!=1.5.7,<2.0)"]
 
 [metadata]
 lock-version = "1.1"
-python-versions = "^3.8"
-content-hash = "d3e77dc879690a47cae30ad0e2bd1743ae758b219c5b4afa4aced37fb5f6a32e"
+python-versions = "^3.9"
+content-hash = "2ecf5397c5750e73e30af77638576f8298c008b7e4a8ea16fdedc721a9e9b2ea"
 
 [metadata.files]
 certifi = [

pyproject.toml

@@ -10,7 +10,7 @@ url = "https://pypi.thecodelabs.de"
 secondary = true
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = "^3.9"
 thecodelabs-baseutils = "^1.7.0"
 spotipy = "2.19.0"