build(flatpak): fix flatpak apt dependency

.github/workflows/build.yml

@@ -50,7 +50,7 @@ jobs:
         run: cargo check
 
   build-linux:
-    if: ${{ github.event_name != 'pull_request' }}
+    # if: ${{ github.event_name != 'pull_request' }} # TODO: Uncomment this line after test
     name: Build [Linux]
     runs-on: ubuntu-latest
     env:
@@ -70,8 +70,9 @@ jobs:
         uses: dsherret/rust-toolchain-file@v1
 
       - name: Install flatpak dependencies
-        if: ${{ github.event_name == 'schedule' }}
+        # if: ${{ github.event_name == 'schedule' }} # TODO: Uncomment this line after test
         run: |
+          sudo apt-get update
           sudo apt-get install -y flatpak flatpak-builder
           sudo flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
           sudo flatpak install -y --noninteractive flathub org.freedesktop.Platform//23.08