Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Bump runc to latest and modify test cases for linux cgroup manager.

**What this PR does / why we need it**:
This PR has 2 commits
- Bumps runc to latest and fixes trailing "/" problem in ExpandSlice of runc
- Fixes the cgroup_manager_linux_tests.go test cases to have "/" as prefix.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes  #59993

**Special notes for your reviewer**:
cc @sjenning @derekwaynecarr 
**Release note**:

```release-note
NONE
```