meson: avoid building executables that won't be installed

When executable() or custom_target() has install: that is conditional as is
false (i.e. not install:true), it won't be built by default. (build_by_default:
defaults to install:). But if that program is added to public_programs, it will
be build by default because it is pulled in by the test, effectively defeating
the disablement.

While at it, make 'ukify' follow the same pattern as 'kernel-install'.
They will be used later together.

meson.build

@@ -2507,7 +2507,9 @@ exe = executable(
                         versiondep],
         install_rpath : rootpkglibdir,
         install : conf.get('ENABLE_ANALYZE') == 1)
-public_programs += exe
+if conf.get('ENABLE_ANALYZE') == 1
+        public_programs += exe
+endif
 
 if want_tests != 'false'
         test('test-compare-versions',
@@ -4353,7 +4355,9 @@ exe = custom_target(
         install : want_kernel_install,
         install_mode : 'rwxr-xr-x',
         install_dir : bindir)
-public_programs += exe
+if want_kernel_install
+        public_programs += exe
+endif
 
 if want_tests != 'false' and want_kernel_install
         test('test-kernel-install',
@@ -4362,15 +4366,15 @@ if want_tests != 'false' and want_kernel_install
              args : [exe.full_path(), loaderentry_install])
 endif
 
-if want_ukify
-   exe = custom_target(
+exe = custom_target(
         'ukify',
         input : 'src/ukify/ukify.py',
         output : 'ukify',
         command : [jinja2_cmdline, '@INPUT@', '@OUTPUT@'],
-        install : true,
+        install : want_ukify,
         install_mode : 'rwxr-xr-x',
         install_dir : rootlibexecdir)
+if want_ukify
    public_programs += exe
 endif