Run GitHub Actions on ARM processors (#43)

[Standard GitHub-hosted runners for public
repositories](https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories)
--> `ubuntu-24.04-arm`

Author: cclauss

.github/workflows/automerge.yml

@@ -10,7 +10,7 @@ on:
   workflow_dispatch:
 jobs:
   Run-Automerge:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04-arm
     if: github.repository == 'arm/arm-toolchain'
     strategy:
       matrix:

.github/workflows/sync_from_upstream.yml

@@ -8,7 +8,7 @@ on:
   workflow_dispatch:
 jobs:
   Fetch-Upstream:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04-arm
     if: github.repository == 'arm/arm-toolchain'
     strategy:
       matrix:

README.md

@@ -8,7 +8,7 @@ Welcome to the Arm Toolchain project!
 This repository contains the source code for the Arm Toolchain
 project, a fork of the LLVM project containing build scripts and
 auxiliary material for building LLVM based toolchains targeting
-Arm for bare-metal or native AArch64 Linux environments. 
+Arm for bare-metal or native AArch64 Linux environments.
 
 ## Goal