Do not validate change-note file names or frontmatter

Presently, the strict filename or frontmatter are not being used; so we're validating them unnecessarily. So, for now, remove these checks until we decide to either do something with them, or delete the code entirely.

Author: mario-campos

pr-checks/changelog/validate.test.ts

@@ -154,26 +154,6 @@ await describe("isValidChangenoteFile", async () => {
     assert.equal(isValidChangenoteFile("non-existent-file.md"), false);
   });
 
-  await it("rejects invalid filename", async () => {
-    await withTmpFile(
-      "fix-bug.md",
-      "---\ncategory: fix\n---\n- Fixed a bug\n",
-      (filePath) => {
-        assert.equal(isValidChangenoteFile(filePath), false);
-      },
-    );
-  });
-
-  await it("rejects missing frontmatter", async () => {
-    await withTmpFile(
-      "2026-01-01-fix-bug.md",
-      "- Fixed a bug\n",
-      (filePath) => {
-        assert.equal(isValidChangenoteFile(filePath), false);
-      },
-    );
-  });
-
   await it("rejects invalid Markdown", async () => {
     await withTmpFile(
       "2026-01-01-fix-bug.md",

pr-checks/changelog/validate.ts

@@ -95,21 +95,7 @@ export function isValidChangenoteFile(filename: string): boolean {
     return false;
   }
 
-  const { data: frontmatter, content } = matter(fileData);
-
-  if (!isValidChangenoteFilename(path.basename(filename))) {
-    isValid = false;
-    console.error(
-      `${filename}: invalid filename; must match pattern YYYY-MM-DD-id.md`,
-    );
-  }
-  if (!hasValidChangenoteCategory(frontmatter)) {
-    isValid = false;
-    const categories = Object.keys(VALID_CHANGE_NOTE_CATEGORIES).join(", ");
-    console.error(
-      `${filename}: invalid category; must be one of: ${categories}`,
-    );
-  }
+  const { content } = matter(fileData);
   if (!isValidChangenoteContent(content)) {
     isValid = false;
     console.error(