Per github docs, run apt-get update (#637)

https://docs.github.com/en/actions/using-github-hosted-runners/customizing-github-hosted-runners

Author: jepler

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Install requirements
       run: |
         if type -path apt-get; then
-            sudo apt-get install gcc-multilib
+            sudo apt update && sudo apt-get install gcc-multilib
         fi
 
     - name: Versions
@@ -84,7 +84,7 @@ jobs:
     - name: Install requirements
       run: |
         if type -path apt-get; then
-            sudo apt-get install gettext librsvg2-bin
+            sudo apt update && sudo apt-get install gettext librsvg2-bin
         else
             brew install gettext librsvg
             echo >>$GITHUB_PATH /usr/local/opt/gettext/bin