Merge branch 'main' into next

# Conflicts:
#	.github/workflows/validate-vendor-versions.yml
#	package.json
#	src/language-css/printer-postcss.js
#	src/language-js/print/assignment.js

changelog_unreleased/css/12393.md

@@ -0,0 +1,27 @@
+#### Fix lowercasing postcss values (#12393 by @niklasvatn)
+
+PostCSS values can start with digits. Prettier interprets this as a number followed by a unit in the example below.
+
+<!-- prettier-ignore -->
+```css
+// Input
+@value 4XLarge 28/36px;
+
+.test {
+  font: 4XLarge Helvetica;
+}
+
+// Prettier stable
+@value 4XLarge 28/36px;
+
+.test {
+  font: 4xlarge Helvetica;
+}
+
+// Prettier main
+@value 4XLarge 28/36px;
+
+.test {
+  font: 4XLarge Helvetica;
+}
+```