fix(ci): make linkspector check optional (#2342)

Author: bitcoin-tools

.github/workflows/validation.yaml

@@ -165,6 +165,8 @@ jobs:
   markdown-links:
     name: Check hyperlinks
     runs-on: ubuntu-latest
+    # TODO: make this mandatory again with nodebuilder issue 2343
+    continue-on-error: true
     steps:
       - uses: actions/checkout@v5
       - name: Run linkspector on markdown