Woops, no need to commit after substitution, also drop buntu 22 build

.github/workflows/build-artifacts.yaml

@@ -8,10 +8,7 @@ on:
 jobs:
   build:
     name: Build nodeos
-    strategy:
-      matrix:
-        os: [ubuntu-20.04, ubuntu-22.04]
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-20.04
     outputs:
       version: ${{ steps.set_version.outputs.version }}
     steps:

plugins/subst_plugin/subst_plugin.cpp

@@ -64,8 +64,6 @@ namespace eosio {
                 o.vm_version = 0;
             });
 
-            db->commit(context.control.pending_block_num());
-
             enabled_substitutions[og_hash] = new_hash;
         }