D2G: CapAdd is no longer needed since #6890

[matt-boris]

We're seeing jobs now fail with Error: invalid config provided: CapAdd and privileged are mutually exclusive options.

+ timeout 3600 podman run -t --name taskcontainer --privileged --cap-add=SYS_PTRACE -v /task_171079401157384/cache0:/builds/worker/checkouts -v /task_171079401157384/cache1:/builds/worker/tooltool-cache --device=/dev/video0 --add-host=taskcluster:127.0.0.1 --net=host -e ENABLE_E10S -e EXTRA_MOZHARNESS_CONFIG -e GECKO_BASE_REPOSITORY -e GECKO_HEAD_REPOSITORY -e GECKO_HEAD_REV -e GECKO_PATH -e HG_STORE_PATH -e MOCHITEST_FLAVOR -e MOZHARNESS_CONFIG -e MOZHARNESS_SCRIPT -e MOZHARNESS_TEST_PATHS -e MOZHARNESS_URL -e MOZILLA_BUILD_URL -e MOZ_AUTOMATION -e MOZ_FETCHES -e MOZ_FETCHES_DIR -e MOZ_NODE_PATH -e MOZ_SCM_LEVEL -e NEED_PULSEAUDIO -e NEED_WINDOW_MANAGER -e PYTHON -e RUN_ID -e SCCACHE_DISABLE -e TASKCLUSTER_CACHES -e TASKCLUSTER_PROXY_URL -e TASKCLUSTER_ROOT_URL -e TASKCLUSTER_UNTRUSTED_CACHES -e TASKCLUSTER_VOLUMES -e TASKCLUSTER_WORKER_LOCATION -e TASK_ID -e TOOLTOOL_CACHE -e TRY_COMMIT_MSG -e TRY_SELECTOR -e WORKING_DIR docker-archive:dockerimage /builds/worker/bin/run-task -- /builds/worker/bin/test-linux.sh --mochitest-suite=mochitest-plain --setpref=media.peerconnection.mtransport_process=false --setpref=network.process.enabled=false --setpref=layers.d3d11.enable-blacklist=false --download-symbols=ondemand
Getting image source signatures
Copying blob sha256:279be8d91457d49bbc92d2514d448167dcb70d4baa7f9688c345a6bc1177b9ac
Copying blob sha256:af5b576a5b7709a534101de812ce165a8a7392911db1a61ebc2042744434026a
Copying blob sha256:548a79621a426b4eb077c926eabac5a8620c454fb230640253e1b44dc7dd7562
Copying blob sha256:53f44de62e30f687351e56d8a541a542dec131d5a23c59425a0758db00394303
Copying blob sha256:1c11abf0598e68db42edb734386308a34ce4bd0b148115bfc557e196c3bdfeb0
[taskcluster 2024-03-18T21:16:37.148Z] [taskcluster-proxy] Successfully refreshed taskcluster-proxy credentials: task-client/PgHxLy1wQYuKFYQ3rDw6Bg/5/on/us-west1/899832266251115534/until/1710797797.031
Copying config sha256:bfb1d6f326275ce22c7e3a63c24ef81b43b0ddcad9b83f18aff8de3d735a698e
Writing manifest to image destination
Storing signatures
Error: invalid config provided: CapAdd and privileged are mutually exclusive options

Perhaps this needs to remove any CapAdd arguments also (see containers/podman#9131 for a similar situation).

Originally posted by @aerickson in #6890 (comment)