PyAPI Doc: fix typos causing untyped parameters

The type for `bpy_struct.keyframe_insert()`'s `options` parameter was
instead applied to a non-existent `flag` parameter.

The description and type for `mathutils.Vector.Repeat()`'s `vector`
parameter was instead applied to a non-existent `tuple` parameter.

Also fix a reference to `BMElemeSeq` instead of `BMElemSeq`.

Ref: !122734

source/blender/python/mathutils/mathutils_Vector.cc

@@ -354,8 +354,8 @@ PyDoc_STRVAR(
     "\n"
     "   Create a vector by repeating the values in vector until the required size is reached.\n"
     "\n"
-    "   :arg tuple: The vector to draw values from.\n"
-    "   :type tuple: :class:`mathutils.Vector`\n"
+    "   :arg vector: The vector to draw values from.\n"
+    "   :type vector: :class:`mathutils.Vector`\n"
     "   :arg size: The size of the vector to be created.\n"
     "   :type size: int\n");
 static PyObject *C_Vector_Repeat(PyObject *cls, PyObject *args)