meson: use install_symlink() where applicable

Now our baseline of meson is 0.62, hence install_symlink() can be used.

Note, install_symlink() implies install_emptydir() for specified
install_dir. Hence, this also drops several unnecessary
install_emptydir() calls.

Note, the function currently does not support 'relative' and 'force' flags,
so several 'ln -frsT' inline calls cannot be replaced.

src/resolve/meson.build

@@ -311,15 +311,14 @@ if conf.get('ENABLE_RESOLVE') == 1
         install_data('resolv.conf',
                      install_dir : libexecdir)
 
-        install_emptydir(sbindir)
-        meson.add_install_script(sh, '-c',
-                                 ln_s.format(bindir / 'resolvectl',
-                                             sbindir / 'resolvconf'))
+        install_symlink('resolvconf',
+                        pointing_to : sbin_to_bin + 'resolvectl',
+                        install_dir : sbindir)
 
         # symlink for backwards compatibility after rename
-        meson.add_install_script(sh, '-c',
-                                 ln_s.format(bindir / 'resolvectl',
-                                             bindir / 'systemd-resolve'))
+        install_symlink('systemd-resolve',
+                        pointing_to : 'resolvectl',
+                        install_dir : bindir)
 endif
 
 custom_target(