Remove llvm-16-tools package prereq

llvm-16 has been removed from Debian testing, and since
http://goto.google.com/spacebeaker-cl/55452 we no longer depend on it.

BUG: 383125140
Bypass-Presubmit-Reason: tested docker build manually
Change-Id: Ic07e611bfc5ba774caf664d0c226d102ca5549fd
diff --git a/install-prereqs.sh b/install-prereqs.sh
index 1d4019a..f0bbb39 100755
--- a/install-prereqs.sh
+++ b/install-prereqs.sh
@@ -44,7 +44,6 @@
     libcunit1-dev
     libc6-dev
     libtool
-    llvm-16-tools
     gcc
     g++
     libelf-dev