CI: Run apt-get update before installing packages

Author: jserv

.github/workflows/main.yml

@@ -7,7 +7,8 @@ jobs:
     - uses: actions/checkout@v4
       continue-on-error: true
     - name: install-texlive
-      run: | 
+      run: |
+        sudo apt-get update
         sudo apt-get install -q -y texlive-full texlive-latex-base
       shell: bash
     - uses: actions/setup-python@v5
@@ -29,4 +30,4 @@ jobs:
           ./concurrency-primer.pdf
         tag_name: ${{ github.ref_name }}
         body: |
-          Changes in this Release
+          Changes in this Release