ci: replace 'graviton3' with 'neoverse_v1' (#49860)

neoverse_v1 matches the name of the stack and more accurately captures
the requirement for these jobs. The relevant runners in GitLab already
bear both tags, so this shouldn't affect how jobs get assigned to runners.

share/spack/gitlab/cloud_pipelines/.gitlab-ci.yml

@@ -188,7 +188,7 @@ default:
 
 .generate-neoverse_v1:
   extends: [ ".generate-base" ]
-  tags: ["spack", "public", "medium", "aarch64", "graviton3"]
+  tags: ["spack", "public", "medium", "aarch64", "neoverse_v1"]
 
 .generate-neoverse-v2:
   extends: [ ".generate-base" ]

share/spack/gitlab/cloud_pipelines/configs/linux/neoverse_v1/ci.yaml

@@ -1,4 +1,4 @@
 ci:
   pipeline-gen:
   - build-job:
-      tags: ["aarch64", "graviton3"]
+      tags: ["aarch64", "neoverse_v1"]