Remove gpuenv and runtest_gpu

They are identical to examples and runtest.

ClimaComms will automatically fix the device

.buildkite/pipeline.yml

@@ -24,12 +24,6 @@ steps:
       - "julia --project=examples -e 'using Pkg; Pkg.precompile()'"
       - "julia --project=examples -e 'using Pkg; Pkg.status()'"
 
-      - echo "--- Instantiate gpu environment"
-      - "julia --project=gpuenv -e 'using Pkg; Pkg.develop(path=\".\")'"
-      - "julia --project=gpuenv -e 'using Pkg; Pkg.instantiate(;verbose=true)'"
-      - "julia --project=gpuenv -e 'using Pkg; Pkg.precompile()'"
-      - "julia --project=gpuenv -e 'using Pkg; Pkg.status()'"
-
     agents:
       slurm_cpus_per_task: 8
     env:
@@ -51,7 +45,7 @@ steps:
           slurm_mem: 48G
 
       - label: "GPU unit tests"
-        command: "julia --color=yes --project=gpuenv test/runtests_gpu.jl"
+        command: "julia --color=yes --project=examples test/runtests.jl"
         agents:
           slurm_gpus: 1
 
@@ -87,6 +81,6 @@ steps:
           slurm_mem: 48G
 
       - label: "GPU benchmarks"
-        command: "julia --color=yes --project=gpuenv perf/benchmark.jl"
+        command: "julia --color=yes --project=examples perf/benchmark.jl"
         agents:
           slurm_gpus: 1