fix: bundle `react-native-pager-view` inside the runtime to avoid Snackager errors

[byCedric]

Why

This is one of the important React Navigation libraries, and should work in Snack.

How

• Vendored react-native-pager-view inside the runtimes.

Test Plan

See if this works on staging:

https://staging-snack.expo.dev/?platform=android&name=header%20button&dependencies=%40expo%2Fvector-icons%40*%2C%40react-native-community%2Fmasked-view%40*%2Creact-native-gesture-handler%40*%2Creact-native-pager-view%40*%2Creact-native-paper%40%5E4.7.2%2Creact-native-reanimated%40*%2Creact-native-safe-area-context%40*%2Creact-native-screens%40*%2Creact-native-tab-view%40%5E3.0.0%2C%40react-navigation%2Fbottom-tabs%406.3.1%2C%40react-navigation%2Fdrawer%406.4.1%2C%40react-navigation%2Felements%401.3.3%2C%40react-navigation%2Fmaterial-bottom-tabs%406.2.1%2C%40react-navigation%2Fmaterial-top-tabs%406.2.1%2C%40react-navigation%2Fnative-stack%406.6.1%2C%40react-navigation%2Fnative%406.0.10%2C%40react-navigation%2Fstack%406.2.1&hideQueryParams=true&sourceUrl=https%3A%2F%2Freactnavigation.org%2Fexamples%2F6.x%2Fsimple-header-button.js