Fix semicolon duplicated at the end of LESS file (#14007)

Fix semicolon duplicated at the end of file

changelog_unreleased/less/14007.md

@@ -0,0 +1,19 @@
+#### Fix semicolon duplicated at the end of LESS file (#14007 by @mvorisek)
+
+<!-- prettier-ignore -->
+```less
+// Input
+@variable: {
+  field: something;
+};
+
+// Prettier stable
+@variable: {
+  field: something;
+}; ;
+
+// Prettier main
+@variable: {
+  field: something;
+};
+```

src/language-css/printer-postcss.js

@@ -101,7 +101,10 @@ function genericPrint(path, options, print) {
       return [node.raw, hardline];
     case "css-root": {
       const nodes = printNodeSequence(path, options, print);
-      const after = node.raws.after.trim();
+      let after = node.raws.after.trim();
+      if (after.startsWith(";")) {
+        after = after.slice(1).trim();
+      }
 
       return [
         nodes,

tests/format/less/less/__snapshots__/jsfmt.spec.js.snap

@@ -83,6 +83,24 @@ a: b;
 ================================================================================
 `;
 
+exports[`issue-11483--never-append-anything.less format 1`] = `
+====================================options=====================================
+parsers: ["less"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+@variable: {
+  field: something;
+};
+
+=====================================output=====================================
+@variable: {
+  field: something;
+};
+
+================================================================================
+`;
+
 exports[`less.less format 1`] = `
 ====================================options=====================================
 parsers: ["less"]

tests/format/less/less/issue-11483--never-append-anything.less

@@ -0,0 +1,3 @@
+@variable: {
+  field: something;
+};