Add ChangeLog entry

Author: eregon

sdk/CHANGELOG.md

@@ -6,6 +6,8 @@ This changelog summarizes major changes between GraalVM SDK versions. The main f
 * GR-65048: GR-65048: Introduced the `-Dpolyglot.engine.allowUnsupportedPlatform=true` system property to enable Truffle to run on unsupported platforms. If this property is enabled then the failure will be suppressed. Please see follow-up errors and warnings for instructions on how to continue. Note that using an unsupported platform will also force the fallback runtime without runtime optimization.
 * GR-66515 If neither a log handler nor the `log.file` option is set on the `Engine.Builder` or `Context.Builder`, Truffle and language log messages will be written to the Context’s error output stream by default. The `log.file` option is now also supported on `Context.Builder`.
 * GR-63588 A new entry (`Invalidated`) was added to the `opt deopt` truffle compilation logs. It is `true` or `false` depending on whether the compilation was also invalidated.
+* GR-66817 Make `--polyglot` the default for language launchers, so there is no need to specify it anymore to use other languages in standalones. As a result, `AbstractLanguageLauncher#getDefaultLanguages()` and `Launcher#canPolyglot()` have been deprecated.
+* GR-65404 Remove `PolyglotLauncher` as it is no longer used.
 
 ## Version 25.0.0
 * GR-60636 Truffle now stops compiling when the code cache fills up on HotSpot. A warning is printed when that happens.