plone/meta: py_versions needs to be spelled in an ugly way.

* With `3.8` you get an error in GitHub Actions: `Error when evaluating 'strategy' for job 'test'. plone/meta/.github/workflows/test.yml@main (Line: 23, Col: 25): Unexpected value '3.8'`
* With `["3.8"]` you get a yaml error running config-package from plone/meta, as it gets spelled like this: `py-versions: '['3.8']'` (Not sure if I have the single or double quotes right.)

.github/workflows/meta.yml

@@ -30,7 +30,7 @@ jobs:
     uses: plone/meta/.github/workflows/test.yml@main
     with:
 
-       py-versions: '3.8'
+       py-versions: '["3.8"]'
   release_ready:
     uses: plone/meta/.github/workflows/release_ready.yml@main
   circular:

.meta.toml

@@ -9,7 +9,7 @@ commit-id = "a89af8f2"
 codespell_skip = "plone-*.cfg"
 
 [github]
-py_versions = "3.8"
+py_versions = "[\"3.8\"]"
 jobs = [
     "qa",
     "test",