Fix typo in coreml_supported_mlprogram_ops.md (microsoft#22004)

### Description
<!-- Describe your changes. -->

Fix typo: ai:onnx -> ai.onnx

### Motivation and Context
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- If it fixes an open issue, please link to the issue here. -->

Typo.

tools/ci_build/github/apple/coreml_supported_mlprogram_ops.md

@@ -27,5 +27,5 @@ Keep in sync with doco generated from /docs/execution-providers/CoreML-Execution
 |ai.onnx:Split|If provided, `splits` must be constant.|
 |ai.onnx:Sub||
 |ai.onnx:Sigmoid||
-|ai:onnx:Tanh||
+|ai.onnx:Tanh||
 |ai.onnx:Transpose||