Update shim to 15.8

Use RockyLinux shim, they have all variants (x86_64, aa64, ia32).
After Windows update KB5041585, the old shim SBAT is not accepted.

Fixes #197.

shim-signed/COPYRIGHT

@@ -1,46 +1,17 @@
-Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Copyright 2012 Red Hat, Inc <mjg@redhat.com>
-Upstream-Name: shim
-Upstream-Contact: Peter Jones <pjones@redhat.com>
-Source: https://github.com/rhboot/shim
 
-Files: *
-Copyright: 2012 Red Hat, Inc
-	2009-2012 Intel Corporation
-License: BSD-2-Clause
-
-Files: debian/po/cs.po
-Copyright: 2018 Michal Simunek <michal.simunek@gmail.com>
-License: BSD-2-Clause
-
-Files: debian/po/de.po
-Copyright: 2017, 2018 Markus Hiereth <markus.hiereth@freenet.de>
-License: BSD-2-Clause
-
-Files: debian/po/fr.po
-Copyright: 2017, 2018 Alban Vidal <alban.vidal@zordhak.fr>
-License: BSD-2-Clause
-
-Files: debian/po/nl.po
-Copyright: 2017, 2018 Frans Spiesschaert <Frans.Spiesschaert@yucom.be>
-License: BSD-2-Clause
-
-Files: debian/po/pt.po
-Copyright: 2017, 2018 Rui Branco <ruipb@debianpt.org>
-License: BSD-2-Clause
-
-License: BSD-2-Clause
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
- .
+
 Redistributions of source code must retain the above copyright
 notice, this list of conditions and the following disclaimer.
- .
+
 Redistributions in binary form must reproduce the above copyright
 notice, this list of conditions and the following disclaimer in the
 documentation and/or other materials provided with the
 distribution.
- .
+
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
@@ -53,3 +24,7 @@ License: BSD-2-Clause
 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Significant portions of this code are derived from Tianocore
+(http://tianocore.sf.net) and are Copyright 2009-2012 Intel
+Corporation.