Setup sync test to be more serial, README tweaks

.github/workflows/test-sync.yml

@@ -87,6 +87,7 @@ jobs:
           build/data/
 
   sync-test-ubuntu-msan:
+    needs: sync-test-ubuntu-tsan
     timeout-minutes: 60
     runs-on: ubuntu-22.04
 
@@ -178,7 +179,7 @@ jobs:
           build/data/
 
   sync-test-ubuntu-ubsan:
-
+    needs: sync-test-ubuntu-msan
     timeout-minutes: 60
     runs-on: ubuntu-22.04
 
@@ -231,7 +232,7 @@ jobs:
           build/data/
 
   sync-test-ubuntu-asan:
-
+    needs: sync-test-ubuntu-ubsan
     timeout-minutes: 60
     runs-on: ubuntu-22.04
 
@@ -284,11 +285,12 @@ jobs:
           build/data/
 
   sync-test-macos:
-
+    needs: sync-test-ubuntu-asan
     timeout-minutes: 120
     runs-on: ${{ matrix.config.os }}
 
     strategy:
+      max-parallel: 1
       matrix:
         config:
           - {os: macos-15-intel, flags: ""}
@@ -358,7 +360,7 @@ jobs:
           build/data/
 
   sync-test-windows-debug-asan:
-
+    needs: sync-test-macos
     timeout-minutes: 60
     runs-on: windows-2022
 
@@ -404,7 +406,7 @@ jobs:
           build/Debug/data/
 
   sync-test-windows-leaks:
-
+    needs: sync-test-windows-debug-asan
     timeout-minutes: 60
     runs-on: windows-2022