fix(scripts): re-spell check-changeset-no-major's older R control through renameRow

Fixes #7164

The rename-row control PR #7048 added asserted only /^R\d/.test(raw.trim()) —
that the diff output begins with an R row, not which two paths git paired.
PR #7157 brought the family's renameRow helper (whole-row match, pinning both
paths) into this file for its own case; this control was the one spelling
left behind. Re-spelled through renameRow(dir, base, '.changeset/old.md',
'.changeset/new.md'), matching the shape check-empty-changeset.mjs and
check-adr-0087-registration.mjs already use, and removed the now-unused raw
binding. No behaviour change.

Author: claude

scripts/check-changeset-no-major.mjs

@@ -1078,10 +1078,9 @@ function selfTest() {
       const oldMinor = '---\n"@objectstack/spec": minor\n---' + long;
       const newMajor = '---\n"@objectstack/spec": major\n---' + long;
       const { dir, base } = makeRepo({ '.changeset/old.md': oldMinor }, { '.changeset/old.md': null, '.changeset/new.md': newMajor });
-      const raw = git(['diff', '--name-status', base, 'HEAD', '--', '.changeset/*.md'], dir);
       assert(
-        /^R\d/.test(raw.trim()),
-        `control: git must really report this as a rename, or the row below is about an ordinary add — got ${JSON.stringify(raw.trim())}`,
+        renameRow(dir, base, '\\.changeset/old\\.md', '\\.changeset/new\\.md') !== null,
+        `control: git must really pair .changeset/old.md with .changeset/new.md as a rename, or the row below is about an ordinary add — got ${JSON.stringify(git(['diff', '--name-status', base, 'HEAD', '--', '.changeset/*.md'], dir))}`,
       );
       const { introduced } = scan({ cwd: dir, base });
       assert(