feat(k8s): Add detect env vars option (#4488)

* feat(k8s): Add detect env vars option

Have added the option to trigger the k8s module based on what env vars
are set, this has been done in a backwards compatible way so if nothing
is changed from the defaults the module will still behave the same way
as before. This is similar to what I did in #4486 for the python module
and if goes well I'd like to rollout to other modules.

* Update src/modules/kubernetes.rs

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

* Update src/modules/kubernetes.rs

---------

Co-authored-by: David Knaack <davidkna@users.noreply.github.com>

.github/config-schema.json

@@ -952,6 +952,7 @@
       "default": {
         "context_aliases": {},
         "contexts": [],
+        "detect_env_vars": [],
         "detect_extensions": [],
         "detect_files": [],
         "detect_folders": [],
@@ -4256,6 +4257,13 @@
             "type": "string"
           }
         },
+        "detect_env_vars": {
+          "default": [],
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
         "contexts": {
           "default": [],
           "type": "array",