build: bump version to 1.12.12

New stable version. Some small fixes and doc updates; big new thing are
the new SCM bindings (under scm/), which will replace the
long-deprecated old bindings (under guile/).

Overall:

- In 'mu init', --my-address has been renamed into --personal-address
  for consistency. The old name still works.

Mu4e:

- Emacs bookmarks can be now also be created for mu4e queries; see
  the mu4e-emacs-bookmark-policy defcustom

- Support dash when completing maildirs

- Add defcustom for mu4e-compose-jump-to-reasonable-place, so it can be
  overridden, e.g. in compose hooks.

- In mu4e, make indexing snappier when there no new messages

SCM:

- Experimental new Guile bindings under scm/, including a reference
  manual and unit tests.

meson.build

@@ -17,7 +17,7 @@
 ################################################################################
 # project setup
 project('mu', ['c', 'cpp'],
-        version: '1.12.11',
+        version: '1.12.12',
         meson_version: '>= 0.56.0',
         license: 'GPL-3.0-or-later',
         default_options : [
@@ -26,9 +26,9 @@ project('mu', ['c', 'cpp'],
           'c_std=c11',
           'cpp_std=c++17'])
 
-# hard-code the date here (for reproducibility); we derive the dates used in e.g.
-# documentation from this.
-mu_date='2025-05-10'
+# hard-code the date here (for reproducibility); we derive the dates used in
+# e.g. documentation from this.
+mu_date='2025-07-19'
 
 # installation paths
 prefixdir = get_option('prefix')