tree-wide: convert dlopen_*() callers to DLOPEN_* wrapper macros

Switch the executable-owned call sites from the plain dlopen_<lib>()
helpers to the new DLOPEN_<LIB>() macros, so that each binary that loads
an optional library at runtime now carries its own .note.dlopen note
instead of relying solely on libsystemd-shared. Each call site passes a
priority reflecting whether it hard-depends on the library (required) or
degrades gracefully without it (recommended).

Co-developed-by: Claude Opus 4.8 <noreply@anthropic.com>

src/sysupdate/sysupdate-partition.c

@@ -161,7 +161,7 @@ int find_suitable_partition(
         POINTER_MAY_BE_NULL(partition_type);
         assert(ret);
 
-        r = dlopen_fdisk(LOG_DEBUG);
+        r = DLOPEN_FDISK(LOG_DEBUG, SD_ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED);
         if (r < 0)
                 return r;
 
@@ -230,7 +230,7 @@ int patch_partition(
         if (change == 0) /* Nothing to do */
                 return 0;
 
-        r = dlopen_fdisk(LOG_DEBUG);
+        r = DLOPEN_FDISK(LOG_DEBUG, SD_ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED);
         if (r < 0)
                 return r;
 

src/sysupdate/sysupdate-resource.c

@@ -234,7 +234,7 @@ static int resource_load_from_blockdev(Resource *rr) {
 
         assert(rr);
 
-        r = dlopen_fdisk(LOG_DEBUG);
+        r = DLOPEN_FDISK(LOG_DEBUG, SD_ELF_NOTE_DLOPEN_PRIORITY_RECOMMENDED);
         if (r < 0)
                 return r;