ci: build: always update cache to avoid out of date packages

APT cache could be out of date leading to a:
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

Fix this by always calling apt-get update before an apt-get install.
Signed-off-by: Clément Péron <peron.clem@gmail.com>

.github/workflows/build.yml

@@ -17,7 +17,9 @@ jobs:
       - uses: actions/checkout@v2
       - name: Install Linux dependencies
         if: startsWith(matrix.os, 'ubuntu')
-        run: sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev
       - name: Install Mac dependencies
         if: startsWith(matrix.os, 'macos')
         run: brew install protobuf automake
@@ -60,7 +62,9 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install dependencies
-        run: sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev valgrind
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev valgrind
       - name: Run distcheck with valgrind
         run: |
           ./autogen.sh
@@ -72,7 +76,9 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install dependencies
-        run: sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev lcov
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev lcov
       - name: Run coverage build
         run: |
           ./autogen.sh
@@ -96,7 +102,9 @@ jobs:
       - uses: actions/checkout@v2
       - name: Install Linux dependencies
         if: startsWith(matrix.os, 'ubuntu')
-        run: sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y protobuf-compiler libprotobuf-dev libprotoc-dev
       - name: Install Mac dependencies
         if: startsWith(matrix.os, 'macos')
         run: brew install protobuf abseil