Remove Jenkins scripts (rapidsai#1143)

Since we've switched to GitHub Actions, this PR removes any old scripts that were used by Jenkins. Additionally it removes/updates any references to `gpuCI`.

Authors:
  - AJ Schmidt (https://github.com/ajschmidt8)

Approvers:
  - Jordan Jacobelli (https://github.com/Ethyling)

URL: rapidsai#1143

Author: ajschmidt8

.github/labeler.yml

@@ -17,5 +17,5 @@ cpp:
   - 'tests/**'
   - 'doxygen/**'
 
-gpuCI:
+ci:
   - 'ci/**'

CONTRIBUTING.md

@@ -56,10 +56,5 @@ contributing to. Start with _Step 3_ from above, commenting on the issue to let
 others know you are working on it. If you have any questions related to the
 implementation of the issue, ask them in the issue instead of the PR.
 
-### Building and Testing on a gpuCI image locally
-
-Before submitting a pull request, you can do a local build and test on your machine that mimics our gpuCI environment using the `ci/local/build.sh` script.
-For detailed information on usage of this script, see [here](ci/local/README.md).
-
 ## Attribution
 Portions adopted from https://github.com/pytorch/pytorch/blob/master/CONTRIBUTING.md

README.md

@@ -1,7 +1,5 @@
 # <div align="left"><img src="img/rapids_logo.png" width="90px"/>&nbsp;RMM: RAPIDS Memory Manager</div>
 
-[![Build Status](https://gpuci.gpuopenanalytics.com/job/rapidsai/job/gpuci/job/rmm/job/branches/job/rmm-branch-pipeline/badge/icon)](https://gpuci.gpuopenanalytics.com/job/rapidsai/job/gpuci/job/rmm/job/branches/job/rmm-branch-pipeline/)
-
 **NOTE:** For the latest stable [README.md](https://github.com/rapidsai/rmm/blob/main/README.md) ensure you are on the `main` branch.
 
 ## Resources