kdump-lib: Drop 'file' dependency in is_uki
    
    Resolves: RHEL-46777
    
    commit 2f21fa2acfac9f6e19e071330f917e60aafc4600
    Author: Philipp Rudo <prudo@redhat.com>
    Date:   Mon Jun 24 17:34:35 2024 +0200
    
        kdump-lib: Drop 'file' dependency in is_uki
    
        The 'file' utility is no longer installed per default. In addition there
        was an update to it so it now reports the file type as
        application/vnd.microsoft.portable-executable. Thus fall back to use
        objdump to avoid adding yet an other dependency for kdump-utils and deal
        with different versions of 'file'.
    
        Note: This has the small drawback that objdump is arch specific. I.e.
        examining a aarch64 UKI on a x86_64 machine will return an 'file format
        not recognized' error.
    
        Signed-off-by: Philipp Rudo <prudo@redhat.com>
    
    Signed-off-by: Philipp Rudo <prudo@redhat.com>