Merge ~gabrielcocenza/juju-lint:basepython into juju-lint:master

[Gabriel Cocenza]

basepython to python3

- Jenkins CI runs on jammy series and func tests are failing
  because of the python interpreter.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[🤖 prod-jenkaas-bootstack (prod-jenkaas-bootstack)]

PASSED: Continuous integration, rev:8a1aa54b03a3004ae13572116f3e621a35575390
https://jenkins.canonical.com/bootstack/job/lp-juju-lint-ci/12/
Executed test runs:
    SUCCESS: https://jenkins.canonical.com/bootstack/job/lp-charm-test-functest/1109/
    None: https://jenkins.canonical.com/bootstack/job/lp-update-mp/1526/

Click here to trigger a rebuild:
https://jenkins.canonical.com/bootstack/job/lp-juju-lint-ci/12//rebuild

review: Approve (continuous-integration)

[Mert Kirpici (mertkirpici)]

thanks for this Gabriel.

For visibility about the discussion we had, I am adding the side effects of this change.
The functional tests have two "modes of operation":
1 - installing the snap and running tests against the cli program provided by the snap
2 - installing the python package to the tox virtualenv and running the cli program provided by the python package.

This change will not have an effect on (1) since the snap is confined, however it will cause the mode (2) to run using the native python interpreter installed the environment which may be different than what the snap "core" has.
The CI system is operating in mode (1).

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision e115361cca6bb4e1148c0fdd91873ff7997deccb

diff --git a/tox.ini b/tox.ini
index ba747d8..4dea114 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ envlist = lint, unit, func
 skip_missing_interpreters = True
 
 [testenv]
-basepython = python3.8
+basepython = python3
 
 [testenv:unit]
 deps =