Replaced yum localinstall with dnf install

* RHEL 7 uses yum but is end of life (2024-06-30)
* RHEL 8/9 uses dnf instead of yum and localinstall is just an
  alias for install. Yum/dnf accepts local files and package
  names with install since RHEL 6, localinstall is deprecated
  and removed in Fedora.
* use uname -m (uname -p returns unknown instead of e.g. x86_64)

Author: GCoreTech

docs/Developer Resources/Custom Packages.rst

@@ -69,6 +69,8 @@ ZFS 2.1 release:
 
    sudo yum install epel-release gcc make autoconf automake libtool rpm-build libtirpc-devel libblkid-devel libuuid-devel libudev-devel openssl-devel zlib-devel libaio-devel libattr-devel elfutils-libelf-devel kernel-devel-$(uname -r) python python2-devel python-setuptools python-cffi libffi-devel ncompress
    sudo yum install --enablerepo=epel dkms python-packaging
+ 
+**NOTE:** RHEL/CentOS 7 is end of life. Use yum instead of dnf for install instructions below.
 
 -  **RHEL/CentOS 8**:
 
@@ -106,7 +108,7 @@ Building rpm-based DKMS and user packages can be done as follows:
    $ cd zfs
    $ ./configure
    $ make -j1 rpm-utils rpm-dkms
-   $ sudo yum localinstall *.$(uname -p).rpm *.noarch.rpm
+   $ sudo dnf install *.$(uname -m).rpm *.noarch.rpm
 
 kmod
 ~~~~
@@ -124,7 +126,7 @@ options.
    $ cd zfs
    $ ./configure
    $ make -j1 rpm-utils rpm-kmod
-   $ sudo yum localinstall *.$(uname -p).rpm
+   $ sudo dnf install *.$(uname -m).rpm *.noarch.rpm
 
 kABI-tracking kmod
 ~~~~~~~~~~~~~~~~~~
@@ -142,7 +144,7 @@ option must be passed to configure.
    $ cd zfs
    $ ./configure --with-spec=redhat
    $ make -j1 rpm-utils rpm-kmod
-   $ sudo yum localinstall *.$(uname -p).rpm
+   $ sudo dnf install *.$(uname -m).rpm *.noarch.rpm
 
 Debian and Ubuntu
 -----------------