Fix CI runners

Author: stevepryde

ci/macos-latest-chrome

@@ -1,2 +1,3 @@
 #!/bin/bash
-brew install --cask google-chrome
+# Chrome and chromedriver are pre-installed on GitHub-hosted macOS runners.
+"$CHROMEWEBDRIVER/chromedriver" --port=9515 &

ci/macos-latest-firefox

@@ -1,2 +1,3 @@
 #!/bin/bash
-brew install --cask firefox
+# Firefox and geckodriver are pre-installed on GitHub-hosted macOS runners.
+"$GECKOWEBDRIVER/geckodriver" --port=4444 &

ci/ubuntu-latest-chrome

@@ -1,4 +1,4 @@
 #!/bin/bash
-wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
-sudo dpkg -i google-chrome-stable_current_amd64.deb
- sudo apt install -f -y
+# Chrome and chromedriver are pre-installed on GitHub-hosted Ubuntu runners.
+# CHROMEWEBDRIVER points at the directory holding the version-matched binary.
+"$CHROMEWEBDRIVER/chromedriver" --port=9515 &

ci/ubuntu-latest-firefox

@@ -1,3 +1,4 @@
 #!/bin/bash
-sudo apt-get update
-sudo apt-get install firefox
+# Firefox and geckodriver are pre-installed on GitHub-hosted Ubuntu runners.
+# GECKOWEBDRIVER points at the directory holding the version-matched binary.
+"$GECKOWEBDRIVER/geckodriver" --port=4444 &

ci/windows-latest-chrome.ps1

@@ -1,2 +1,3 @@
-# Fix: sometimes, Chrome is updated but its checksum is not. Ignore this mismatch.
-choco install googlechrome --ignore-checksums -y
+# Chrome and chromedriver are pre-installed on GitHub-hosted Windows runners.
+Start-Process -FilePath "$env:CHROMEWEBDRIVER\chromedriver.exe" -ArgumentList "--port=9515"
+Start-Sleep -Seconds 1

ci/windows-latest-firefox.ps1

@@ -1 +1,3 @@
-choco install firefox
+# Firefox and geckodriver are pre-installed on GitHub-hosted Windows runners.
+Start-Process -FilePath "$env:GECKOWEBDRIVER\geckodriver.exe" -ArgumentList "--port=4444"
+Start-Sleep -Seconds 1