ci: add g++ and libc6-dev, use v4 image (verified locally)

.gitea/workflows/ci.yaml

@@ -5,7 +5,7 @@ on: [push, pull_request]
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
-    container: gitea.tap-tap.win/taptap/fastsync-ci:v3
+    container: gitea.tap-tap.win/taptap/fastsync-ci:v4
     steps:
       - name: Checkout
         uses: actions/checkout@v4

Dockerfile

@@ -1,6 +1,6 @@
 FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    gcc cmake make libzstd-dev git ca-certificates curl && \
+    gcc g++ make libc6-dev cmake libzstd-dev git ca-certificates curl && \
     curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
     apt-get install -y --no-install-recommends nodejs && \
     rm -rf /var/lib/apt/lists/*