# Why

This PR introduces ccache for Android builds. It speeds up the most
demanding task for Android builds, which is cpp compilation.

# Results

- **Hit rate: 87%** - that's the percentage of c++ files which didn't
have to be compiled.
- **Build time drop:** My tests showed a **4-minute** reduction in build
time. This time varies based on runner performance, so the most precise
numbers will be visible after some time in our performance metrics.

# How

- Downloads ccache.
- Replaces the default compiler with ccache.
- Adds custom configuration for ccache, which is described in the
comments.

# Test Plan
Green CI, tested on a stacked PR.

# Why

This PR introduces ccache for iOS builds. It speeds up the compilation
of .cpp, .mm, and .m files.

# Results

- **Hit rate for subsequent clean builds: ~100% (2436 files)** the
percentage of files that didn't have to be compiled.
- **Drop in build time:** my tests showed around a **10-minute**
reduction. This time varies based on runner performance, so more precise
numbers will be available later in performance metrics.

# How
- Downloads ccache.
 - Forces Xcode to use ccache for compilation.
- Adds custom configuration for ccache, described in the YAML file
comments.

# Test Plan

Green CI, tested on a stacked PR.

# Why
Changes to the following packages:
- create-expo
- create-expo-nightly
- create-expo-module
- @expo/cli 

shouldn't trigger the test suite 

# How
Adds new negations to paths which trigger the workflow and to
`common-paths` in `Detect build-relevant platform changes`

# Test Plan
Green CI