ci: doc: upload build log for debugging

When PDF build fails, we want to see what cmaused the failure, so upload
the log for later analysis.

Signed-off-by: Anas Nashif <[email protected]>

Author: nashif

.github/workflows/doc-build.yml

@@ -156,6 +156,7 @@ jobs:
         west init -l .
 
     - name: build-docs
+      continue-on-error: true
       run: |
         if [[ "$GITHUB_REF" =~ "refs/tags/v" ]]; then
           DOC_TAG="release"
@@ -166,7 +167,11 @@ jobs:
         DOC_TAG=${DOC_TAG} SPHINXOPTS="-q -j auto" LATEXMKOPTS="-quiet -halt-on-error" make -C doc pdf
 
     - name: upload-build
+      if: always()
       uses: actions/upload-artifact@v3
       with:
         name: pdf-output
-        path: doc/_build/latex/zephyr.pdf
+        if-no-files-found: ignore
+        path: |
+          doc/_build/latex/zephyr.pdf
+          doc/_build/latex/zephyr.log