refactor(database): remove unused sentry__run_write_cache

The retry system writes cache files directly via its own paths.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jpnurmi

src/sentry_database.c

@@ -163,17 +163,6 @@ sentry__run_write_external(
     return write_envelope(run->external_path, envelope);
 }
 
-bool
-sentry__run_write_cache(
-    const sentry_run_t *run, const sentry_envelope_t *envelope)
-{
-    if (sentry__path_create_dir_all(run->cache_path) != 0) {
-        SENTRY_ERRORF("mkdir failed: \"%s\"", run->cache_path->path);
-        return false;
-    }
-    return write_envelope(run->cache_path, envelope);
-}
-
 bool
 sentry__run_move_cache(
     const sentry_run_t *run, const sentry_path_t *src, const char *dst)

src/sentry_database.h

@@ -64,14 +64,6 @@ bool sentry__run_write_session(
  */
 bool sentry__run_clear_session(const sentry_run_t *run);
 
-/**
- * This will serialize and write the given envelope to disk into a file named
- * like so:
- * `<database>/cache/<event-uuid>.envelope`
- */
-bool sentry__run_write_cache(
-    const sentry_run_t *run, const sentry_envelope_t *envelope);
-
 /**
  * Moves `src` to `<database>/cache/<dst>`. If `dst` is NULL, the filename of
  * `src` is used.