Remove or move some expensive low-value testing (#65453)

When PGO was added, I added it in PR as well just to help with monitoring
At this point it's very stable and expensive to run, so we should probably move it out.

Single-file is still tested in our unit tests, but these runs were mainly to test the
compatibility of APIs with single-file. We've found that the analyzer does a pretty good
job of verifying that without testing, and we still have verification via NativeAOT, which
I think is a superset of the testing as a whole.

eng/pipelines/runtime.yml

@@ -160,21 +160,6 @@ jobs:
  jobParameters:
  testGroup: innerloop
 
-#
-# Build PGO CoreCLR release
-#
-- template: /eng/pipelines/common/platform-matrix.yml
- parameters:
- jobTemplate: /eng/pipelines/coreclr/templates/build-job.yml
- buildConfig: release
- platforms:
- - windows_x64
- - windows_x86
- - Linux_x64
- jobParameters:
- testGroup: innerloop
- pgoType: 'PGO'
-
 #
 # Build CoreCLR Formatting Job
 # Only when CoreCLR is changed, and only in the 'main' branch (no release branches;
@@ -652,27 +637,6 @@ jobs:
  creator: dotnet-bot
  testRunNamePrefixSuffix: Mono_$(_BuildConfig)
 
-# Build and test libraries under single-file publishing
-- template: /eng/pipelines/common/platform-matrix.yml
- parameters:
- jobTemplate: /eng/pipelines/common/global-build-job.yml
- helixQueuesTemplate: /eng/pipelines/libraries/helix-queues-setup.yml
- buildConfig: Release
- platforms:
- - windows_x64
- - Linux_x64
- jobParameters:
- testGroup: innerloop
- isSingleFile: true
- nameSuffix: SingleFile
- buildArgs: -s clr+libs+libs.tests -c $(_BuildConfig) /p:TestSingleFile=true /p:ArchiveTests=true
- timeoutInMinutes: 120
- # extra steps, run tests
- extraStepsTemplate: /eng/pipelines/libraries/helix.yml
- extraStepsParameters:
- creator: dotnet-bot
- testRunNamePrefixSuffix: SingleFile_$(_BuildConfig)
-
 #
 # Build Mono and Installer on LLVMJIT mode
 #
@@ -1025,22 +989,6 @@ jobs:
  liveRuntimeBuildConfig: release
  liveLibrariesBuildConfig: ${{ variables.debugOnPrReleaseOnRolling }}
 
-#
-# PGO Build
-#
-- template: /eng/pipelines/installer/installer-matrix.yml
- parameters:
- buildConfig: Release
- jobParameters:
- isOfficialBuild: ${{ variables.isOfficialBuild }}
- liveRuntimeBuildConfig: release
- liveLibrariesBuildConfig: ${{ variables.debugOnPrReleaseOnRolling }}
- pgoType: 'PGO'
- platforms:
- - windows_x64
- - windows_x86
- - Linux_x64
-
 #
 # CoreCLR Test builds using live libraries release build
 # Only when CoreCLR is changed