Merge bitcoin#22994: ci: use Debian Bullseye in ARM CI

252d1a7 ci: use Debian Bullseye in ARM CI (fanquake)

Pull request description:

  This works around an issue when trying to use `std::filesystem::remove_all` with the ARM GCC on Buster.  Has been split out of bitcoin#20744.

  See commentary starting here: bitcoin#20744 (comment).
  Also: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93201.

ACKs for top commit:
  MarcoFalke:
    cr ACK 252d1a7
  hebasto:
    ACK 252d1a7, I have reviewed the code and it looks OK, I agree it can be merged.

Tree-SHA512: ca71f5cb07fe06c1c7f0160935e667ffeb62bd6a1a89b54124b5633c5c176347a2207aaa5eca68938ed89db9778d357e42b677115d4ed386fa2d7d2ffa5025ad

.cirrus.yml

@@ -65,10 +65,10 @@ task:
   lint_script:
     - ./ci/lint_run_all.sh
 task:
-  name: 'ARM [unit tests, no functional tests] [buster]'
+  name: 'ARM [unit tests, no functional tests] [bullseye]'
   << : *GLOBAL_TASK_TEMPLATE
   arm_container:
-    image: debian:buster
+    image: debian:bullseye
     cpu: 2
     memory: 8G
   env: