CI: Disable AppStream metadata downloads to fix mirror sync failures

All CI failures were caused by dep11 (AppStream metadata) files failing
to download during Ubuntu mirror synchronization. These files contain
GUI application metadata and are unnecessary for headless CI builds.
- Add IndexTargets::deb::Contents-deb::DefaultEnabled=false
- Add IndexTargets::deb-src::Contents-deb-src::DefaultEnabled=false
- Keep Acquire::Retries=3 for actual package download resilience
- Add || true fallback for arm64 job to handle edge cases

Author: jserv

.github/workflows/main.yml

@@ -69,13 +69,10 @@ jobs:
 
     - name: Install dependencies
       run: |
-            # Retry apt-get update to handle transient mirror sync issues
-            for i in 1 2 3; do
-              sudo apt-get update -q=2 -o Acquire::Retries=3 && break || {
-                echo "apt-get update attempt $i failed, retrying..."
-                sleep 5
-              }
-            done
+            # Disable AppStream metadata to avoid mirror sync failures (dep11 files not needed for CI)
+            sudo apt-get update -q=2 -o Acquire::Retries=3 \
+              -o Acquire::IndexTargets::deb::Contents-deb::DefaultEnabled=false \
+              -o Acquire::IndexTargets::deb-src::Contents-deb-src::DefaultEnabled=false
             sudo apt-get install -q=2 -o Acquire::Retries=3 curl libsdl2-dev libsdl2-mixer-dev device-tree-compiler expect bc p7zip-full
       shell: bash
 
@@ -307,13 +304,10 @@ jobs:
         githubToken: ${{ github.token }}
         # No 'sudo' is available
         install: |
-          # Retry apt update to handle transient mirror sync issues
-          for i in 1 2 3; do
-            apt update -qq -o Acquire::Retries=3 && break || {
-              echo "apt update attempt $i failed, retrying..."
-              sleep 5
-            }
-          done
+          # Disable AppStream metadata to avoid mirror sync failures (dep11 files not needed for CI)
+          apt update -qq -o Acquire::Retries=3 \
+            -o Acquire::IndexTargets::deb::Contents-deb::DefaultEnabled=false \
+            -o Acquire::IndexTargets::deb-src::Contents-deb-src::DefaultEnabled=false || true
           apt install -yqq -o Acquire::Retries=3 make git curl wget clang libsdl2-dev libsdl2-mixer-dev lsb-release software-properties-common gnupg bc
           which wget || echo "WARNING: wget not found after installation"
         # FIXME: gcc build fails on Aarch64/Linux hosts
@@ -323,9 +317,9 @@ jobs:
         run: |
           # Verify and install wget if needed (workaround for install step issues)
           if ! command -v wget > /dev/null 2>&1; then
-            for i in 1 2 3; do
-              apt update -qq -o Acquire::Retries=3 && break || sleep 5
-            done
+            apt update -qq -o Acquire::Retries=3 \
+              -o Acquire::IndexTargets::deb::Contents-deb::DefaultEnabled=false \
+              -o Acquire::IndexTargets::deb-src::Contents-deb-src::DefaultEnabled=false || true
             apt install -yqq -o Acquire::Retries=3 wget
           fi
           git config --global --add safe.directory ${{ github.workspace }}
@@ -585,13 +579,10 @@ jobs:
     # LLVM static analysis
     - name: set up scan-build
       run: |
-            # Retry apt-get update to handle transient mirror sync issues
-            for i in 1 2 3; do
-              sudo apt-get update -q=2 -o Acquire::Retries=3 && break || {
-                echo "apt-get update attempt $i failed, retrying..."
-                sleep 5
-              }
-            done
+            # Disable AppStream metadata to avoid mirror sync failures (dep11 files not needed for CI)
+            sudo apt-get update -q=2 -o Acquire::Retries=3 \
+              -o Acquire::IndexTargets::deb::Contents-deb::DefaultEnabled=false \
+              -o Acquire::IndexTargets::deb-src::Contents-deb-src::DefaultEnabled=false
             sudo apt-get install -q=2 -o Acquire::Retries=3 curl libsdl2-dev libsdl2-mixer-dev
             .ci/fetch.sh -q -o llvm.sh https://apt.llvm.org/llvm.sh
             chmod +x ./llvm.sh