Delete check-legacy-links-format.yml (#12471)

Remove the check-legacy-links-format.yml workflow. These checks are now included as part of our
content conformance checks that run on PRs with documentation content changes.

.github/workflows/check-legacy-links-format.yml

@@ -1,17 +0,0 @@
-name: Legacy Link Format Checker
-
-on:
-  push:
-    paths:
-      - "website/content/**/*.mdx"
-      - "website/data/*-nav-data.json"
-
-jobs:
-  check-links:
-    uses: hashicorp/dev-portal/.github/workflows/docs-content-check-legacy-links-format.yml@475289345d312552b745224b46895f51cc5fc490
-    with:
-      repo-owner: "hashicorp"
-      repo-name: "packer"
-      commit-sha: ${{ github.sha }}
-      mdx-directory: "website/content"
-      nav-data-directory: "website/data"