[CI] Disable early swift driver/syntax on Linux presets

Allow Linux builds on a host with Swift installed. This will allow us to
PR test enabling the early swift driver/syntax builds (once the Linux
docker images are updated).

Author: bnbarham

utils/build-presets.ini

@@ -881,6 +881,10 @@ installable-package=%(installable_package)s
 # in Linux CI bots
 relocate-xdg-cache-home-under-build-subdir
 
+# Temporarily disable early swift driver/syntax builds so that linux images
+# can use the swift release images as a base.
+skip-early-swift-driver
+skip-early-swiftsyntax
 
 [preset: buildbot_linux_base]
 mixin-preset=