qmk find: Fix failure with multiple filters (qmk#22497)

When multiple `-f FILTER` options were specified, `qmk find` did not
return anything at all instead of printing the list of entries that
matched all of the specified filters.

The problem was that the statement in `_filter_keymap_targets()` that
filled `targets` had a wrong indent and therefore was executed for every
filter instead of only once after applying all filters, and
`valid_keymaps` was actually an iterator and therefore could be used
only once.  Moving the statement outside of the loop fixes the problem.

lib/python/qmk/search.py

@@ -172,7 +172,7 @@ def f(e):
                 cli.log.warning(f'Unrecognized filter expression: {filter_expr}')
                 continue
 
-            targets = [KeyboardKeymapBuildTarget(keyboard=e[0], keymap=e[1], json=e[2]) for e in valid_keymaps]
+        targets = [KeyboardKeymapBuildTarget(keyboard=e[0], keymap=e[1], json=e[2]) for e in valid_keymaps]
 
     return targets