Promote prod to 1.3.3 (#687)

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## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
Promotes prod to 1.3.3, the main changes are making mcpb package version
optional and also fixing the enforced schema validation.

## How Has This Been Tested?
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tested? -->

## Breaking Changes
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## Types of changes
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the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
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that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
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Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

deploy/Pulumi.gcpProd.yaml

@@ -1,7 +1,7 @@
 config:
   mcp-registry:environment: prod
   mcp-registry:provider: gcp
-  mcp-registry:imageTag: 1.3.2  # Set specific image tag for production (change this to deploy different versions)
+  mcp-registry:imageTag: 1.3.3  # Set specific image tag for production (change this to deploy different versions)
   gcp:project: mcp-registry-prod
   mcp-registry:githubClientId: Iv23liUydBbI7Z2Q9bOZ
   mcp-registry:githubClientSecret: