WL#4979: Remove instance manager from builds

Remove instance manager from builds.
In MySQL 5.4.0

See also BUG#33472, "Instance Manager ("mysqlmanager") still shows up in the
start/stop script", which needs to be fixed in Azalea (5.4.4 or later) but
not in 5.4.0.

Instance manager deprecated in 5.1 and removed
in 6.0; this task is to do the same removal in
5.4.0 for forward-compatibility. See also
WL#4104 "Deprecate the Instance Manager" and 
WL#4085 "Discontinue the Instance Manager".

For 5.4.1, it's confirmed that Instance Manager
is removed -- it was necessary to remove IM
from the installer definition in order to build
5.4.1 Windows binaries.

Instance manager deprecated in 5.1 and removed
in 6.0; this task is to do the same removal in
5.4.0 for forward-compatibility. See also
WL#4104 "Deprecate the Instance Manager" and 
WL#4085 "Discontinue the Instance Manager".

No further LLD needed.