fix: numAttemptsPerPriority in provider-fallback.md (#1030)

**Description**

Fix numPerAttemptPriority in the example config in provider-fallback.md

**Related Issues/PRs (if applicable)**
#881 


**Special notes for reviewers (if applicable)**
After fix the position of `numAttemptsPerPriority` still get error

`Error from server (BadRequest): error when creating "STDIN":
BackendTrafficPolicy in version "v1alpha1" cannot be handled as a
BackendTrafficPolicy: strict decoding error: unknown field
"spec.retry.numAttemptsPerPriority`

Removed numAttemptsPerPriority works fine.

---------

Signed-off-by: Xiaolin Lin <[email protected]>

Author: xiaolin593

ai-gateway-crds-helm-v0.0.0-latest.tgz

@@ -91,16 +91,16 @@ spec:
       kind: HTTPRoute
       name: provider-fallback # HTTPRoute is created with the same name as AIGatewayRoute
   retry:
+    # This ensures that only one attempt is made per priority.
+    # For example, if the primary backend fails, it will not retry on the same backend.
+    numAttemptsPerPriority: 1
     numRetries: 5
     perRetry:
       backOff:
         baseInterval: 100ms
         maxInterval: 10s
       timeout: 30s
     retryOn:
-      # This ensures that only one attempt is made per priority.
-      # For example, if the primary backend fails, it will not retry on the same backend.
-      numAttemptsPerPriority: 1
       httpStatusCodes:
         - 500
       triggers: