For push notification, we can now use just Production Certificate for 2 environments (production and sandbox) instead of Development and Production certificates.
Now for code signing, with Xcode 11 https://developer.apple.com/documentation/xcode_release_notes/xcode_11_release_notes we can just use Apple Development and Apple Distribution certificate for multiple platforms
Signing and capabilities settings are now combined within a new Signing & Capabilities tab in the Project Editor. The new tab enables using different app capabilities across multiple build configurations. The new capabilities library makes it possible to search for available capabilities
Xcode 11 supports the new Apple Development and Apple Distribution certificate types. These certificates support building, running, and distributing apps on any Apple platform. Preexisting iOS and macOS development and distribution certificates continue to work, however, new certificates you create in Xcode 11 use the new types. Previous versions of Xcode don’t support these certificates