[clang] [analyzer] Remove overzealous "No dispatcher registered" assertion (PR #107294)

[via cfe-commits]

================
@@ -0,0 +1,10 @@
+// RUN: %clang_analyze_cc1 -w -analyzer-checker=nullability \
+// RUN:                       -analyzer-output=text -verify %s
+//
+// expected-no-diagnostics
+//
+// This case previously crashed because of an assert in CheckerManager.cpp,
+// checking for registered event dispatchers. This check is too strict so
+// was removed by this commit. This test case covers the previous crash,
+// and is expected to simply not crash. The source file can be anything,
+// and does not need to be empty.
----------------
vabridgers wrote:

I resolved this with the latest update. 

https://github.com/llvm/llvm-project/pull/107294