[openwrt/openwrt] ci: bump buildworker container to version v6

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch openwrt-23.05:
https://git.openwrt.org/37395ecb3214f6c086668b9f1a3c3405e06acfe8

commit 37395ecb3214f6c086668b9f1a3c3405e06acfe8
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Fri May 26 11:38:24 2023 +0200

    ci: bump buildworker container to version v6
    
    Its being used by buildbot workers, adds g++-multilib to fix node
    cross-compilation from a 64-bit build machine to 32-bit host.
    
    References: https://github.com/openwrt/buildbot/pull/7
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
    (cherry picked from commit 567784127e92ba6f9291adb1a546f567e50d9850)
---
 .github/workflows/Dockerfile.tools | 2 +-
 .github/workflows/build-tools.yml  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/Dockerfile.tools b/.github/workflows/Dockerfile.tools
index df5892618a..5d365fc56d 100644
--- a/.github/workflows/Dockerfile.tools
+++ b/.github/workflows/Dockerfile.tools
@@ -1,4 +1,4 @@
-FROM ghcr.io/openwrt/buildbot/buildworker-v3.8.0:v2
+FROM ghcr.io/openwrt/buildbot/buildworker-v3.8.0:v6
 
 COPY --chown=buildbot staging_dir/host /prebuilt_tools/staging_dir/host
 COPY --chown=buildbot build_dir/host /prebuilt_tools/build_dir/host
diff --git a/.github/workflows/build-tools.yml b/.github/workflows/build-tools.yml
index 9b865f2608..0629b1b62a 100644
--- a/.github/workflows/build-tools.yml
+++ b/.github/workflows/build-tools.yml
@@ -13,7 +13,7 @@ jobs:
   build:
     name: Build tools
     runs-on: ubuntu-latest
-    container: ghcr.io/openwrt/buildbot/buildworker-v3.8.0:v2
+    container: ghcr.io/openwrt/buildbot/buildworker-v3.8.0:v6
 
     steps:
       - name: Checkout