Add release note for mdn#10691

RELEASE_NOTES.md

@@ -10,7 +10,7 @@ RELEASE DATE TK
 
   <details>
 
-  <summary>New features from <code>SVGFilterPrimitiveStandardAttributes</code></summary>
+  <summary>New features ex-<code>SVGFilterPrimitiveStandardAttributes</code></summary>
 
   - `api.SVGFEBlendElement.height`
   - `api.SVGFEBlendElement.result`
@@ -100,6 +100,19 @@ RELEASE DATE TK
 
   </details>
 
+- The mixin `api.SVGTests` has been removed and replaced by features representing its exposed interfaces. ([#10691](https://github.com/mdn/browser-compat-data/pull/10691))
+
+  <details>
+
+  <summary>New features ex-<code>api.SVGTests</code></summary>
+
+  - `api.SVGAnimationElement.requiredExtensions`
+  - `api.SVGAnimationElement.systemLanguage`
+  - `api.SVGGraphicsElement.requiredExtensions`
+  - `api.SVGGraphicsElement.systemLanguage`
+
+  </details>
+
 - The following non-existent, long-removed, or otherwise irrelevant features have been removed:
 
   - `api.Document.undoManager` ([#10581](https://github.com/mdn/browser-compat-data/pull/10581))