Add workflow_dispatch event to GitHub Actions

This commit introduces the `workflow_dispatch` event into the Build EfficientDynamoDb and Build AWS SDK credentials compatibility package workflows. This addition allows these workflows to be triggered manually from the Actions tab in GitHub.

.github/workflows/build.yml

@@ -1,6 +1,7 @@
 name: Build EfficientDynamoDb
 
 on:
+  workflow_dispatch:
   push:
     branches:
       - devtekve

.github/workflows/build_creds_aws_sdk.yml

@@ -1,6 +1,7 @@
 name: Build AWS SDK credentials compatibility package
 
 on:
+  workflow_dispatch:
   push:
     branches:
       - devtekve