doc: Remove duplicate copyright line.

emixa-d · emixa-d · commit 46685fab293b · 2023-09-09T12:37:32.000+02:00
Looks like the conflicts in 1b0ce83 weren't fixed completely correctly. * fibers.texi: Do it.
diff --git a/fibers.texi b/fibers.texi
@@ -14,7 +14,6 @@ This manual is for Fibers (version @value{VERSION}, updated
 @noindent
 Copyright 2016-2023 Andy Wingo@*
 Copyright 2021, 2023 Maxime Devos@*
-Copyright 2021, 2023 Maxime Devos@*
 Copyright 2022, 2023 Aleix Conchillo Flaqué
 
 @quotation
