Wrong method to httpRequestCustomizer.customize in HttpClientStreamableHttpTransport

[johnyannj]

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Bug description

HttpClientStreamableHttpTransport.java

var builder = requestBuilder.uri(uri)
	.header("Accept", APPLICATION_JSON + ", " + TEXT_EVENT_STREAM)
	.header("Content-Type", APPLICATION_JSON)
	.header("Cache-Control", "no-cache")
	.header(HttpHeaders.PROTOCOL_VERSION, MCP_PROTOCOL_VERSION)
	.POST(HttpRequest.BodyPublishers.ofString(jsonBody));
return Mono.from(this.httpRequestCustomizer.customize(builder, "GET", uri, jsonBody));

Environment
version 0.11.0

Steps to reproduce
see code

Expected behavior

httpRequestCustomizer.customize(builder, "POST", uri, jsonBody));

Minimal Complete Reproducible example
..