build: s/Sanitizers_COMPILER_OPTIONS/Sanitizers_COMPILE_OPTIONS

this change addresses a regression introduced by ed88919, which
renamed the exported CMake variable of `Sanitizers_COMPILER_OPTIONS`
to `Sanitizers_COMPILE_OPTIONS`, to be more consistent with the
names used by CMake. but it failed to update the top-level
`CMakeLists.txt`, which was still using the old name to populate
this setting down to .pc. that's why some parent project fails to
link with the latest seastar with sanitizers enabled.

in this change, we correct the variable name.

Signed-off-by: Kefu Chai <[email protected]>

CMakeLists.txt

@@ -883,7 +883,7 @@ if (condition)
   if (NOT Sanitizers_FOUND)
     message (FATAL_ERROR "Sanitizers not found!")
   endif ()
-  set (Seastar_Sanitizers_OPTIONS ${Sanitizers_COMPILER_OPTIONS})
+  set (Seastar_Sanitizers_OPTIONS ${Sanitizers_COMPILE_OPTIONS})
   target_link_libraries (seastar
     PUBLIC
       $<${condition}:Sanitizers::address>