Revert "chore:re-add spectral rule (#217)"

This reverts commit dd68f96.

tools/spectral/.spectral.yaml

@@ -184,17 +184,6 @@ rules:
           field: allow_diff
           pattern: "^true$"
 
-   no-slash-before-custom-method:
-    description: "Custom methods (e.g., ':applyItem') should not be preceded by a '/'."
-    message: "The path '{{path}}' contains a '/' before a custom method. Custom methods should not start with a '/'."
-    severity: error
-    given: "$.paths"
-    then:
-      field: "@key"
-      function: pattern
-      functionOptions:
-        notMatch: "/[^/]+/:[a-zA-Z]+$"
-
 overrides:
   - files: # load sample data has an issue with different path param names for different VERBS
       - "*.yaml#/paths/~1api~1atlas~1v1.0~1groups~1%7BgroupId%7D~1sampleDatasetLoad~1%7BsampleDatasetId%7D"