Revert "fix: update test scripts for palm"

The Github runners are working now, so switch back to using them instead
of 2U self-hosted workers which are only guaranteed to work on master
and will probably stop working on the Palm branch at some point.

This reverts commit de62e38.

.github/workflows/unit-tests-gh-hosted.yml

@@ -9,7 +9,7 @@ on:
 
 jobs:
   run-test:
-    if: github.repository != 'openedx/edx-platform' && github.repository != 'edx/edx-platform-private'
+    if: (github.repository != 'openedx/edx-platform' && github.repository != 'edx/edx-platform-private') || (github.repository == 'openedx/edx-platform' && (startsWith(github.base_ref, 'open-release') == true))
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
@@ -79,7 +79,7 @@ jobs:
         uses: ./.github/actions/unit-tests
 
   collect-and-verify:
-    if: github.repository != 'openedx/edx-platform' && github.repository != 'edx/edx-platform-private'
+    if: (github.repository != 'openedx/edx-platform' && github.repository != 'edx/edx-platform-private') || (github.repository == 'openedx/edx-platform' && (startsWith(github.base_ref, 'open-release') == true))
     runs-on: ubuntu-20.04
     strategy:
       matrix:

.github/workflows/unit-tests.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   run-tests:
     name: python-${{ matrix.python-version }},django-${{ matrix.django-version }},${{ matrix.shard_name }}
-    if: github.repository == 'edx/edx-platform-private' || github.repository == 'openedx/edx-platform'
+    if: (github.repository == 'edx/edx-platform-private') || (github.repository == 'openedx/edx-platform' && (startsWith(github.base_ref, 'open-release') == false))
     runs-on: [ edx-platform-runner ]
     strategy:
       matrix:

.github/workflows/verify-gha-unit-tests-count.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   collect-and-verify:
-    if: github.repository == 'edx/edx-platform-private' || github.repository == 'openedx/edx-platform'
+    if: (github.repository == 'edx/edx-platform-private') || (github.repository == 'openedx/edx-platform' && (startsWith(github.base_ref, 'open-release') == false))
     runs-on: [ edx-platform-runner ]
     steps:
       - name: sync directory owner