CHANGELOG: Add entry for SigningConfig API changes

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

Author: jku

CHANGELOG.md

@@ -42,6 +42,9 @@ All versions prior to 0.9.0 are untracked.
   * ClientTrustConfig now provides methods `production()`, `staging()`and `from_tuf()`
     to get access to current client configuration (trusted keys & certificates,
     URLs and their validity periods). [#1363](https://github.com/sigstore/sigstore-python/pull/1363)
+  * SigningConfig now has methods that return actual clients (like `RekorClient`) instead of
+    just URLs. The returned clients are also filtered according to SigningConfig contents.
+    [#1407](https://github.com/sigstore/sigstore-python/pull/1407)
 * `--trust-config` now requires a file with SigningConfig v0.2, and is able to fully
   configure the used Sigstore instance [#1358]/(https://github.com/sigstore/sigstore-python/pull/1358)
 * By default (when `--trust-config` is not used) the whole trust configuration now