bitbake: checksum/fetch2: Switch from persist_data to a standard cache file

The sqlite connection handling is causing problems with python 3.13. The
connection can be closed at gc time which causing warnings and those
can appear at 'random' points and break output, causing weird failures
in different tinfoil tools and other tests.

Using sqlite as an IPC was never a great idea so drop that usage entirely
and just use the standard cache mechanism we already have for other
situations.

(Bitbake rev: fdc55bb649cb77456d0ac48a9600ef289a52af18)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cache.py

@@ -847,6 +847,16 @@ class MultiProcessCache(object):
         data = [{}]
         return data
 
+    def clear_cache(self):
+        if not self.cachefile:
+            bb.fatal("Can't clear invalid cachefile")
+
+        self.cachedata = self.create_cachedata()
+        self.cachedata_extras = self.create_cachedata()
+        with bb.utils.fileslocked([self.cachefile + ".lock"]):
+            bb.utils.remove(self.cachefile)
+            bb.utils.remove(self.cachefile + "-*")
+
     def save_extras(self):
         if not self.cachefile:
             return