Update configuration-options.mdx (#18015)

making it clear cannot edit ciphers.

Author: mbullock1986

src/content/docs/spectrum/reference/configuration-options.mdx

@@ -118,7 +118,7 @@ If you have the TLS termination setting configured to **off**, this means that S
 
 Below are the cipher suites Cloudflare presents to origins during an SSL/TLS handshake. For cipher suites supported at our edge or presented to browsers and other user agents, refer to [Cipher suites](/ssl/edge-certificates/additional-options/cipher-suites/).
 
-The cipher suites below are ordered based on how they appear in the ClientHello, communicating our preference to the origin.
+The cipher suites below are ordered based on how they appear in the ClientHello, communicating our preference to the origin. Customers do not have the ability to modify the ciphers used by Spectrum.
 
 ## Supported cipher suites by protocol