feat(datasource): Add python-version datasource (#27583)

lib/modules/datasource/api.ts

lib/modules/datasource/python-version/__fixtures__/eol.json

...dules/datasource/python-version/__fixtures__/release.json

lib/modules/datasource/python-version/common.ts

lib/modules/datasource/python-version/index.spec.ts

lib/modules/datasource/python-version/index.ts

lib/modules/datasource/python-version/readme.md

lib/modules/datasource/python-version/schema.ts

lib/util/cache/package/types.ts