Update dependency postcss to v8.4.26 (#26030)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

yarn.lock

@@ -9248,9 +9248,9 @@ postcss-value-parser@^4.1.0, postcss-value-parser@^4.2.0:
   integrity sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==
 
 postcss@^8.2.15, postcss@^8.4.24:
-  version "8.4.25"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.25.tgz#4a133f5e379eda7f61e906c3b1aaa9b81292726f"
-  integrity sha512-7taJ/8t2av0Z+sQEvNzCkpDynl0tX3uJMCODi6nT3PfASC7dYCWV9aQ+uiCf+KBD4SEFcu+GvJdGdwzQ6OSjCw==
+  version "8.4.26"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.26.tgz#1bc62ab19f8e1e5463d98cf74af39702a00a9e94"
+  integrity sha512-jrXHFF8iTloAenySjM/ob3gSj7pCu0Ji49hnjqzsgSRa50hkWCKD0HQ+gMNJkW38jBI68MpAAg7ZWwHwX8NMMw==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"