"There are ... branches"

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Author: hugovk

developer-workflow/development-cycle.rst

@@ -68,7 +68,7 @@ Maintenance branches
 A branch for a previous feature release, currently being maintained for bug
 fixes, or for the next feature release in its
 :ref:`beta <beta>` or :ref:`release candidate <rc>` stages.
-There is usually either one or two maintenance branches at any given time.
+There are usually either one or two maintenance branches at any given time.
 After the final release of a new minor version (3.x.0), releases
 produced from a maintenance branch are called **bugfix** or **maintenance**
 releases; the terms are used interchangeably. These releases have a