reduce max-parallel

Author: Roman

.github/workflows/check-btcli-tests.yml

@@ -97,7 +97,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
-      max-parallel: 16
+      max-parallel: 8
       matrix:
         rust-branch:
           - stable

.github/workflows/check-sdk-tests.yml

@@ -96,7 +96,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
-      max-parallel: 16
+      max-parallel: 8
       matrix:
         rust-branch:
           - stable