Use debian:oldstable-slim as build runtime container

.github/workflows/build.yml

@@ -116,14 +116,25 @@ jobs:
   linux:
     name: 'Linux'
     runs-on: ubuntu-latest
-    container: s1lentq/linux86buildtools:latest
+    container: debian:oldstable-slim
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
+      - name: Install dependencies
+        run: |
+          dpkg --add-architecture i386
+          apt-get update
+          apt-get install -y \
+            gcc-multilib g++-multilib \
+            build-essential \
+            libc6-dev libc6-dev-i386 \
+            git cmake rsync \
+            g++ gcc
+
       - name: Build and Run unittests
         run: |
           rm -rf build && cmake -DCMAKE_BUILD_TYPE=Unittests -B build && cmake --build build -j8