Fix SwiftUI Section builder issues for Swift 6 migration

[dylans2010]

Motivation

• Swift 6's stricter @ViewBuilder inference rejects non-View expressions placed directly in Section bodies, causing build errors during migration.
• The codebase contained let bindings and computed expressions inside Section closures which must be moved or wrapped so the Section body only returns views.

Description

• Wrapped the content rows in FilePreviewView's "Content" Section with a Group and removed an inline let so the Section body contains only view-producing code (SwiftCode/Views/Utilities/FilePreviewView.swift).
• Moved the filtered deployment logs out of the Section body into a computed property deploymentLogs and updated the Section to use it (SwiftCode/Views/Developer/DeploymentDebug/DeploymentDebugView.swift).
• Moved the source-branch commit derivation out of the Section body into a computed property sourceBranchCommits and updated the Section to iterate that property (SwiftCode/Views/Collaboration/PRCreateView.swift).
• Overall changes ensure Section closures contain only view-building code and avoid non-View bindings that trigger Swift 6 builder errors.

Testing

• Attempted xcodebuild -project SwiftCode.xcodeproj -list, but it failed because Xcode CLI tools are not available in the environment (xcodebuild: command not found), so a full build/test could not be executed.
• Verified repository modifications and created a commit (git commit) successfully, indicating the patches applied cleanly.
• No automated unit or integration test runs were executed due to the missing Xcode toolchain in this environment.

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Codex Task

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