chore(ci): remove usage of self-hosted runners (#6170)

Author: galargh

.github/workflows/ci.yml

@@ -18,12 +18,7 @@ env:
 jobs:
   test:
     name: Test ${{ matrix.crate }}
-    runs-on: ${{ fromJSON(
-      github.repository == 'libp2p/rust-libp2p' && (
-        (contains(fromJSON('["libp2p-webrtc", "libp2p"]'), matrix.crate) && '["self-hosted", "linux", "x64", "2xlarge"]') ||
-        (contains(fromJSON('["libp2p-quic", "libp2p-perf"]'), matrix.crate) && '["self-hosted", "linux", "x64", "xlarge"]') ||
-        '["self-hosted", "linux", "x64", "large"]'
-      ) || '"ubuntu-latest"') }}
+    runs-on: ubuntu-latest
     timeout-minutes: 10
     needs: gather_published_crates
     strategy:

.github/workflows/interop-test.yml

@@ -13,7 +13,7 @@ jobs:
   run-transport-interop:
     name: Run transport interoperability tests
     if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name == github.repository
-    runs-on: ${{ fromJSON(github.repository == 'libp2p/rust-libp2p' && '["self-hosted", "linux", "x64", "4xlarge"]' || '"ubuntu-latest"') }}
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         flavour: [chromium, native]