chore(deps): bump postcss from 8.5.15 to 8.5.26 in /docs (#28145)

Bumps [postcss](https://github.com/postcss/postcss) from 8.5.15 to 8.5.26.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.5.15...8.5.26)

---
updated-dependencies:
- dependency-name: postcss
  dependency-version: 8.5.25
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs/yarn.lock

@@ -1365,7 +1365,7 @@ mj-context-menu@^0.6.1:
   resolved "https://registry.npmjs.org/mj-context-menu/-/mj-context-menu-0.6.1.tgz"
   integrity sha512-7NO5s6n10TIV96d4g2uDpG7ZDpIhMh0QNfGdJw/W47JswFcosz457wqz/b5sAKvl12sxINGFCn80NZHKwxQEXA==
 
-nanoid@^3.3.12:
+nanoid@^3.3.17:
   version "3.3.18"
   resolved "https://registry.yarnpkg.com/nanoid/-/nanoid-3.3.18.tgz#f66a2de1199ffde0fcf21c8a5f13106b1c081913"
   integrity sha512-DTg4MJbGMWkfi6VZFdNt2/caMbQy4Ou+Op/hJQvGEWcnVfoA1QA+xzRKAzw9jD6+GVOOeYr/mIcuDSdug6F6+w==
@@ -1464,11 +1464,11 @@ picocolors@^1.1.1:
   integrity sha512-xceH2snhtb5M9liqDsmEw56le376mTZkEX/jEb/RxNFyegNul7eNslCXP9FDj/Lcu0X8KEyMceP2ntpaHrDEVA==
 
 postcss@^8.4.43, postcss@^8.5.15:
-  version "8.5.15"
-  resolved "https://registry.npmjs.org/postcss/-/postcss-8.5.15.tgz"
-  integrity sha512-FfR8sjd4em2T6fb3I2MwAJU7HWVMr9zba+enmQeeWFfCbm+UOC/0X4DS8XtpUTMwWMGbjKYP7xjfNekzyGmB3A==
+  version "8.5.26"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.5.26.tgz#6e75135780c7e10df3433bf2266c552d35c8c620"
+  integrity sha512-u82N74LFzG8ca+dD8puPnplTXoGH4fTPpVGuIbt36G3qvNlkvfD0lEAZSxaly3KX8TS/L1A1gsCEmvKmBcVbkQ==
   dependencies:
-    nanoid "^3.3.12"
+    nanoid "^3.3.17"
     picocolors "^1.1.1"
     source-map-js "^1.2.1"