chore(ci): run non dependent bootstrap build steps in parallel (#13454)

## Overview

Over time some steps have been added to bootstrap build that do not
depend on what came before

We should run these steps in parallel

Author: Maddiaa0

bootstrap.sh

@@ -187,14 +187,18 @@ function build {
   # Ensure we have yarn set up.
   corepack enable
 
-  projects=(
+  # These projects are dependant on each other and must be built linearly
+  dependent_projects=(
     noir
     barretenberg
     avm-transpiler
     noir-projects
     # Relies on noir-projects for verifier solidity generation.
     l1-contracts
     yarn-project
+  )
+  # These projects rely on the output of the dependant projects and can be built in parallel
+  non_dependent_projects=(
     boxes
     playground
     docs
@@ -203,9 +207,13 @@ function build {
     aztec-up
   )
 
-  for project in "${projects[@]}"; do
+  echo_header "Building dependent projects in serial"
+  for project in "${dependent_projects[@]}"; do
     $project/bootstrap.sh ${1:-}
   done
+
+  echo_header "build non-dependent projects in parallel"
+  parallel --line-buffer --tag --halt now,fail=1 '{}/bootstrap.sh ${1:-}' ::: ${non_dependent_projects[@]}
 }
 
 function bench {