[jsinterp] Fix splice to handle float

Needed for new youtube js player f1ca6900
Closes #1767

test/test_youtube_signature.py

@@ -78,6 +78,10 @@ _NSIG_TESTS = [
         'https://www.youtube.com/s/player/2dfe380c/player_ias.vflset/en_US/base.js',
         'oBo2h5euWy6osrUt', '3DIBbn3qdQ',
     ),
+    (
+        'https://www.youtube.com/s/player/f1ca6900/player_ias.vflset/en_US/base.js',
+        'cu3wyu6LQn2hse', 'jvxetvmlI9AN9Q',
+    ),
 ]
 
 

yt_dlp/jsinterp.py

@@ -397,7 +397,7 @@ class JSInterpreter(object):
                 elif member == 'splice':
                     assertion(isinstance(obj, list), 'must be applied on a list')
                     assertion(argvals, 'takes one or more arguments')
-                    index, howMany = (argvals + [len(obj)])[:2]
+                    index, howMany = map(int, (argvals + [len(obj)])[:2])
                     if index < 0:
                         index += len(obj)
                     add_items = argvals[2:]