Revert "Unbreak android CI by moving to ubuntu-latest (#57216)"

This reverts the runner changes from #57216, moving the Android CI jobs
back from `ubuntu-latest` to the dedicated `4-core-ubuntu` / `8-core-ubuntu`
runners.

Goal: measure whether the dedicated runners speed up RN's CI compared to
`ubuntu-latest`.

Note: `nightly.yml` was deleted and `publish-npm.yml` was restructured on
main since #57216 landed, so those two files are intentionally left
untouched; this revert only covers the per-PR CI jobs.

Author: cortinico

.github/workflows/e2e-android-rntester.yml

@@ -16,7 +16,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: 4-core-ubuntu
     outputs:
       status: ${{ steps.report-status.outputs.status }}
     strategy:

.github/workflows/e2e-android-templateapp.yml

@@ -16,7 +16,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: 4-core-ubuntu
     outputs:
       status: ${{ steps.report-status.outputs.status }}
     strategy:

.github/workflows/fantom-tests.yml

@@ -16,7 +16,7 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: 8-core-ubuntu
     outputs:
       status: ${{ steps.report-status.outputs.status }}
     container:

.github/workflows/test-all.yml

@@ -218,7 +218,7 @@ jobs:
     secrets: inherit
 
   build_fantom_runner:
-    runs-on: ubuntu-latest
+    runs-on: 8-core-ubuntu
     needs: [set_release_type, check_code_changes, lint]
     if: needs.check_code_changes.outputs.any_code_change == 'true'
     container:
@@ -261,7 +261,7 @@ jobs:
     secrets: inherit
 
   build_android:
-    runs-on: ubuntu-latest
+    runs-on: 8-core-ubuntu
     needs: [set_release_type, check_code_changes]
     if: |
       needs.check_code_changes.outputs.any_code_change == 'true' &&
@@ -307,7 +307,7 @@ jobs:
     secrets: inherit
 
   build_npm_package:
-    runs-on: ubuntu-latest
+    runs-on: 8-core-ubuntu
     needs:
       [
         set_release_type,
@@ -340,7 +340,7 @@ jobs:
           skip-apple-prebuilts: ${{ needs.check_code_changes.outputs.should_test_ios == 'false' }}
 
   test_android_helloworld:
-    runs-on: ubuntu-latest
+    runs-on: 4-core-ubuntu
     needs: [build_npm_package, build_android]
     if: ${{ always() && needs.build_android.result == 'success' && needs.build_npm_package.result == 'success' }}
     container: