Version 9.4.

- Drop upstreamed -eclib patch.
- Drop unnecessary -readonly patch.
- Unbundle ipywidgets.
- Bundle memory_allocator for now.

sagemath-cremona.patch

@@ -1,6 +1,6 @@
 diff -up src/sage/databases/cremona.py.orig src/sage/databases/cremona.py
---- src/sage/databases/cremona.py.orig	2021-05-09 16:00:11.000000000 -0600
-+++ src/sage/databases/cremona.py	2021-05-28 11:39:00.005575551 -0600
+--- src/sage/databases/cremona.py.orig	2021-08-22 02:44:33.000000000 -0600
++++ src/sage/databases/cremona.py	2021-08-26 13:33:03.200366675 -0600
 @@ -885,7 +885,8 @@ class MiniCremonaDatabase(SQLDatabase):
                  message = "There is no elliptic curve with label " \
                      + label + " in the default database; try installing " \
@@ -11,11 +11,11 @@ diff -up src/sage/databases/cremona.py.orig src/sage/databases/cremona.py
              raise ValueError(message)
          ainvs = eval(c[0])
          data = {'cremona_label': label,
-@@ -1663,6 +1664,7 @@ class LargeCremonaDatabase(MiniCremonaDa
+@@ -1670,6 +1671,7 @@ class LargeCremonaDatabase(MiniCremonaDa
              con.executemany("UPDATE t_curve SET gens=? WHERE curve=?",
                  curve_data)
              print("Committing...")
 +            self.commit()
-             if largest_conductor and int(v[0]) > largest_conductor: break
- 
+             if largest_conductor and int(v[0]) > largest_conductor:
+                 break