Convert function declarations to C23 standard
https://bugs.gentoo.org/944457
--- a/src/cache.c
+++ b/src/cache.c
@@ -1359,7 +1359,7 @@
 /**
  * Callback function for Cache_delayed_process_queue.
  */
-static void Cache_delayed_process_queue_callback()
+static void Cache_delayed_process_queue_callback(void *data)
 {
    CacheEntry_t *entry;
 
--- a/src/jpeg.c
+++ b/src/jpeg.c
@@ -124,7 +124,7 @@
  *    static void init_source(j_decompress_ptr cinfo)
  * (declaring it with no parameter avoids a compiler warning)
  */
-static void init_source()
+static void init_source(struct jpeg_decompress_struct *cinfo)
 {
 }
 
@@ -181,7 +181,7 @@
  *    static void term_source(j_decompress_ptr cinfo)
  * (declaring it with no parameter avoids a compiler warning)
  */
-static void term_source()
+static void term_source(struct jpeg_decompress_struct *cinfo)
 {
 }