feat(python): Add detect env vars option (#4486)

feat(python): Configure different detect env vars

Allow the env vars that trigger the python module to be configured, if
an empty list is passed then the module will fall back to just
triggering based on the configured files, folders and extensions.

.github/config-schema.json

@@ -1396,6 +1396,9 @@
     },
     "python": {
       "default": {
+        "detect_env_vars": [
+          "VIRTUAL_ENV"
+        ],
         "detect_extensions": [
           "py"
         ],
@@ -5258,6 +5261,15 @@
           "items": {
             "type": "string"
           }
+        },
+        "detect_env_vars": {
+          "default": [
+            "VIRTUAL_ENV"
+          ],
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
         }
       },
       "additionalProperties": false