fix(deps): update dependency postcss-nesting to v12 (#1472)

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

plugins/plugin-site/package.json

@@ -92,7 +92,7 @@
     "postcss-css-variables": "0.19.0",
     "postcss-import": "15.1.0",
     "postcss-merge-rules": "6.0.1",
-    "postcss-nesting": "11.3.0",
+    "postcss-nesting": "12.0.0",
     "postcss-preset-env": "9.1.0",
     "postcss-pxtorem": "6.0.0",
     "postcss-url": "10.1.3",

yarn.lock

@@ -2575,15 +2575,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@csstools/selector-specificity@npm:^2.0.0":
-  version: 2.2.0
-  resolution: "@csstools/selector-specificity@npm:2.2.0"
-  peerDependencies:
-    postcss-selector-parser: ^6.0.10
-  checksum: 97c89f23b3b527d7bd51ed299969ed2b9fbb219a367948b44aefec228b8eda6ae0ad74fe8a82f9aac8ff32cfd00bb6d0c98d1daeab2e8fc6d5c4af25e5be5673
-  languageName: node
-  linkType: hard
-
 "@csstools/selector-specificity@npm:^3.0.0":
   version: 3.0.0
   resolution: "@csstools/selector-specificity@npm:3.0.0"
@@ -3229,7 +3220,7 @@ __metadata:
     postcss-css-variables: 0.19.0
     postcss-import: 15.1.0
     postcss-merge-rules: 6.0.1
-    postcss-nesting: 11.3.0
+    postcss-nesting: 12.0.0
     postcss-preset-env: 9.1.0
     postcss-pxtorem: 6.0.0
     postcss-url: 10.1.3
@@ -16871,19 +16862,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss-nesting@npm:11.3.0":
-  version: 11.3.0
-  resolution: "postcss-nesting@npm:11.3.0"
-  dependencies:
-    "@csstools/selector-specificity": ^2.0.0
-    postcss-selector-parser: ^6.0.10
-  peerDependencies:
-    postcss: ^8.4
-  checksum: bc8f59e8114f21ec3fcbd0661072f3e706f25dc5300a925863485a0ab82950c48b75c1fed9548acddc924fa479ab7277b55fcdcc33eb0fe1742b389683479384
-  languageName: node
-  linkType: hard
-
-"postcss-nesting@npm:^12.0.0":
+"postcss-nesting@npm:12.0.0, postcss-nesting@npm:^12.0.0":
   version: 12.0.0
   resolution: "postcss-nesting@npm:12.0.0"
   dependencies: