FiniteStateMachine.disjoint_union: fix doctests

[cheuberg]

In FiniteStateMachine.disjoint_union, doctests had Automata with output letters. Remove those output letters.

Furthermore, fix the labels of the states in the final example in order to be more robust with respect to random order of the states due to sets used in determinisation. Otherwise, a minor modification in #19199 would lead to other labels and breaking the doctest.

Depends on #18966 Depends on #19204

CC: @sagetrac-skropf @dkrenn

Component: finite state machines

Keywords: disjoint_union

Author: Clemens Heuberger

Branch/Commit: 2278303

Reviewer: Daniel Krenn

Issue created by migration from https://trac.sagemath.org/ticket/19201

[cheuberg]

Branch: u/cheuberg/fsm/disjoint_union_doctests

[cheuberg]

Commit: 04c9311

[cheuberg]

New commits:

04c9311

Trac #19201: FiniteStateMachine.disjoint_union: fix doctests

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Branch pushed to git repo; I updated commit sha1. New commits:

23c9573	Trac #18966: Merge #18964 (Kleene star), #18981 (completion), #18965 (concatenation)
5dceb30	Trac #18966: Implement Automaton.complement
c67540a	Fix doctests
b1a6b60	Trac #18966: Fix doctests
985b456	Trac #19204: Implement Automaton.is_equivalent
af42518	Trac #19201: Merge #19204 (Automaton.is_equivalent)
2278303	Trac #19201: Rewrite doctest using is_equivalent

[7ed8c4ca-6d56-4ae9-953a-41e42b4ed313]

Changed commit from 04c9311 to 2278303

[cheuberg]

Dependencies: #18966, #19204

[dkrenn]

comment:5

Is ok.

[dkrenn]

Reviewer: Daniel Krenn

[vbraun]

Changed branch from u/cheuberg/fsm/disjoint_union_doctests to 2278303