Infrastructure: Remove Application Insights output and review dependencies

## 🚨 Infrastructure and Best Practices Updates - Propagation from functions-quickstart-dotnet-azd PR #18

This issue tracks infrastructure and best practices changes that need to be applied to maintain consistency across Azure Functions AZD templates, based on [PR #18](https://github.com/Azure-Samples/functions-quickstart-dotnet-azd/pull/18) merged on August 7, 2025.

### Required Changes

#### 1. 🏗️ Remove Application Insights from Bicep Outputs
Remove this line from `infra/main.bicep`:

```bicep
// REMOVE this line
output APPLICATIONINSIGHTS_CONNECTION_STRING string = monitoring.outputs.name
```

#### 2. 📦 Update Python Package Dependencies (if applicable)
Review and update Python dependencies in `requirements.txt` to their latest stable versions:

```txt
# Update these to latest versions as appropriate
azure-functions
azure-functions-worker
```

#### 3. 🔍 Review for Development-Only Configuration
Ensure no development-specific configuration is included in template files:
- Remove any hardcoded connection strings
- Remove development-only environment variables
- Ensure secrets are properly externalized

### Impact
- **Security:** Removes exposed configuration from template
- **Compatibility:** Updates to latest stable versions
- **Consistency:** Aligns with current best practices across all Azure Functions AZD templates

### Reference
- **Source PR:** https://github.com/Azure-Samples/functions-quickstart-dotnet-azd/pull/18
- **Author:** @nzthiago
- **Scope:** Part of batch propagation across 19 Azure Functions AZD templates

### Related Language-Specific Templates
Similar infrastructure updates needed for all language variants:
- TypeScript templates (4 repositories)
- JavaScript templates (2 repositories)
- PowerShell templates (2 repositories)
- Java templates (1 repository)

/cc @nzthiago

Start with infra/main.bicep and remove the specified Application Insights output, then inspect requirements.txt and the remaining template files for dependency versions and development-only configuration. Compare the repository with the referenced functions-quickstart-dotnet-azd PR; done means the output is absent, dependencies are reviewed, and hardcoded or development-only settings and secrets are not present.

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