[release] Release version 2.8.0

[ci] Update action versions to silence GitHub warnings

[efi] Ignore new LoongArch PC-relative relocations and relaxations

[efi] Add potentially missing relocation types

[efi] Fix Coverity warning about unintended sign extension

[qa] Add option to run tests without KVM acceleration

[build] Fix building with newer binutils

[efi] Fix forced text mode output with multiple displays

[ci] Include tested binaries in uploaded artifacts

[ci] Update to actions/upload-artifact@v3 to silence GitHub warnings

[build] Support building with the clang compiler

[build] Attempt to respect external tool choices

[build] Automatically guess an appropriate cross-compilation prefix

[build] Remove separate invocations of ranlib

[build] Remove redundant invocations of objcopy