[enterprise-4.12] Issue in file installing/installing_bare_metal_ipi/ipi-install-prerequisites.adoc

Typos in this assembly around the use and markup for `bare-metal network` and `provisioning network`
- Incorrect use of the term bare-metal network. It should be `bare metal network` as bare metal is a noun in this context. See https://github.com/openshift/openshift-docs/pull/58242#discussion_r1166901683
- Remove markup for the updated term bare metal network. 
- Remove markup for `provisioning` in provisioning network
Markup only required for instances where the provisioningNetwork might be referring to a field in YAML. Same with bm network.

4.10+

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No markup around the terms bare metal network and provisioning network. The term bare-metal network should be updated to bare metal network. 

Probably more instances outside of this assembly...