Update SteviaLayout.podspec

Updates podspec

Merge pull request #182 from birdsongapps/master

fixes for iOS 26

Merge pull request #173 from freshOS/testing

Testing

Merge pull request #172 from freshOS/swift_6

Swift 6

Bumps to Swift 5.9

Adds PrivacyInfo.xcprivacy

Replaces deprecated @_functionBuilder by @resultBuilder

Merge pull request #155 from edulpn/layoutAnchorOperators

Create Int and CGFloat variants for SteviaLayoutAnchor operators

Updates for Xcode 12 (swift-tools-version:5.3)