fix(exposures): upgrade negative matcher to strictly scoped DSL and fix yaml indentation

Author: vatsalgargg

http/exposures/configs/laravel-env.yaml

@@ -55,11 +55,9 @@ http:
           - "(?mi)^DB_(HOST|PASSWORD|DATABASE)="
         condition: or
 
-      - type: word
-        part: header
-        words:
-          - "text/html"
-        negative: true
+      - type: dsl
+        dsl:
+          - "!contains(tolower(content_type), 'text/html')"
 
       - type: status
         status: