Bump xu-cheng/latex-action (#368)

Bumps the all-github-actions group in /.github/workflows with 1 update: [xu-cheng/latex-action](https://github.com/xu-cheng/latex-action).


Updates `xu-cheng/latex-action` from 3 to 4
- [Release notes](https://github.com/xu-cheng/latex-action/releases)
- [Commits](xu-cheng/latex-action@v3...v4)

---
updated-dependencies:
- dependency-name: xu-cheng/latex-action
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all-github-actions
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/doc.yml

@@ -16,7 +16,7 @@ jobs:
         with:
           ref: ${{ github.head_ref }}
       - name: Compile LaTeX document
-        uses: xu-cheng/latex-action@v3
+        uses: xu-cheng/latex-action@v4
         with:
           root_file: masterdoc.tex
           working_directory: doc/latex