Release shim 15.6 rc1 · rhboot/shim

What's Changed

MokManager: removed Locate graphic output protocol fail error message by @joeyli in #441
shim: implement SBAT verification for the shim_lock protocol by @chrisccoulson in #456
post-process-pe: Fix a missing return code check by @vathpela in #462
Update github actions matrix to be more useful by @frozencemetery in #469
Add f36 and centos9 CI builds by @vathpela in #470
post-process-pe: Fix format string warnings on 32-bit platforms by @steve-mcintyre in #464
tests: also look for system headers in multi-arch directories by @steve-mcintyre in #466
tests: fix gcc warnings by @akodanev in #463
Allow MokListTrusted to be enabled by default by @esnowberg in #455
Add code of conduct by @frozencemetery in #427
Re-add ARM AArch64 support by @vathpela in #468
Use ASCII as fallback if Unicode Box Drawing characters fail by @vathpela in #428
make: don't treat cert.S specially by @vathpela in #475
shim: use SHIM_DEVEL_VERBOSE when built in devel mode by @vathpela in #474
Break out of the inner sbat loop if we find the entry. by @vathpela in #476
Support loading additional certificates by @esnowberg in #446
Add support for NX (W^X) mitigations. by @vathpela in #459
Misc fixups from scan-build. by @vathpela in #477
Fix preserve_sbat_uefi_variable() logic by @jsetje in #478

Full Changelog: 15.5...15.6-rc1