Replacing no-longer-supported-verbage from the website (#12611)

Thanks to @loic-sharma for bringing this to my attention with his PR.

---------

Co-authored-by: Parker Lougheed <[email protected]>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: 3 people

src/content/release/breaking-changes/eliminating-nullok-parameters.md

@@ -2,7 +2,7 @@
 title: Eliminating nullOk Parameters
 description: >
     To eliminate nullOk parameters to help with
-    API sanity in the face of null safety.
+    API clarity in the face of null safety.
 ---
 
 {% render "docs/breaking-changes.md" %}

src/content/release/breaking-changes/supplemental-maybeOf-migration.md

@@ -1,7 +1,7 @@
 ---
 title: Migrate `of` to non-nullable return values, and add `maybeOf`
 description: >
-  To eliminate nullOk parameters to help with API sanity
+  To eliminate nullOk parameters to help with API clarity
   in the face of null safety.
 ---
 

src/content/release/release-notes/changelogs/changelog-1.7.8.md

@@ -341,7 +341,7 @@ From Wed May 1 16:56:00 2019 -0700 to Thu Jul 18 08:04:00 2019 -0700
 
 [32914](https://github.com/flutter/flutter/pull/32914) Make hover and focus not respond when buttons and fields are disabled. (cla: yes, f: material design, framework)
 
-[32936](https://github.com/flutter/flutter/pull/32936) Add some sanity to the ImageStream listener API (a: images, cla: yes, framework)
+[32936](https://github.com/flutter/flutter/pull/32936) Add clarity to the ImageStream listener API (a: images, cla: yes, framework)
 
 [32950](https://github.com/flutter/flutter/pull/32950) Material allows "select all" when not collapsed (cla: yes, f: material design, ▣ platform-android)
 

src/content/release/release-notes/release-notes-1.7.8.md

@@ -236,7 +236,7 @@ In this release, we continue to polish animations, scrolling and image support.
 *   [#33627](https://github.com/flutter/flutter/pull/33627) SliverFillRemaining flag for different use cases
 *   [#32853](https://github.com/flutter/flutter/pull/32853) Add onBytesReceived callback to consolidateHttpClientResponseBytes()
 *   [#32857](https://github.com/flutter/flutter/pull/32857) Add debugNetworkImageHttpClientProvider
-*   [#32936](https://github.com/flutter/flutter/pull/32936) Add some sanity to the ImageStream listener API
+*   [#32936](https://github.com/flutter/flutter/pull/32936) Add clarity to the ImageStream listener API
 *   [#33729](https://github.com/flutter/flutter/pull/33729) Update consolidateHttpClientResponseBytes() to use compressionState
 *   [#33369](https://github.com/flutter/flutter/pull/33369) Add loading support to Image