e2e: run tests in fewer groups (#6742)

.github/workflows/e2e-nightly-master.yml

@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         p2p: ['legacy', 'new', 'hybrid']
-        group: ['00', '01', '02', '03']
+        group: ['00', '01']
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
@@ -35,7 +35,7 @@ jobs:
       - name: Generate testnets
         working-directory: test/e2e
         # When changing -g, also change the matrix groups above
-        run: ./build/generator -g 4 -d networks/nightly/${{ matrix.p2p }} -p ${{ matrix.p2p }} 
+        run: ./build/generator -g 2 -d networks/nightly/${{ matrix.p2p }} -p ${{ matrix.p2p }} 
 
       - name: Run ${{ matrix.p2p }} p2p testnets in group ${{ matrix.group }}
         working-directory: test/e2e