Doc: update deprecations and envars for leapp-repository v0.19.0

See related leapp-repository PRs:
* oamg/leapp-repository#1093
* oamg/leapp-repository#1097
* oamg/leapp-repository#1107

Author: pirat89

docs/source/el7toel8/deprecation.md

@@ -14,6 +14,15 @@ framework, see [List of deprecated functionality in leapp](../deprecation.html#l
 
 - nothing yet...
 
+## v0.19.0 <span style="font-size:0.5em; font-weight:normal">(till March 2024)</span>
+
+- Models
+  - **InstalledTargetKernelVersion** - Deprecated as the new solution has been designed to be able to handle new changes in RHEL 9.3+ system. Use the `InstalledTargetKernelInfo` message instead.
+  - **GrubInfo.orig_device_name** - The `GrubInfo` message is still valid, but the `orig_device_name` field has been deprecated as multiple devices can exist on a system. Use `GrubInfo.orig_devices` instead.
+- Shared libraries
+  - **leapp.libraries.common.config.version.is_rhel_realtime()** - The function has been deprecated as the information cannot be easily determined based on the information inside `IPUConfig`. Use data in the `KernelInfo` message instead, the field `type`.
+  - **leapp.libraries.common.grub.get_grub_device()** - The function has been deprecated as multiple grub devices can exists on a system. Use the `leapp.libraries.common.grub.get_grub_devices()` function instead.
+
 ## v0.16.0 <span style="font-size:0.5em; font-weight:normal">(till September 2022)</span>
 
 - Shared libraries

docs/source/el7toel8/envars.md

@@ -188,3 +188,7 @@ on the system. Currently it works only for the most simple configurations
 storage is not handled anyhow during the upgrade, so it's possible that the network
 based storage will not be correctly initialized and usable as expected).
 
+## LEAPP_DEVEL_KEEP_DISK_IMGS
+If set to 1, leapp will skip removal of disk images created for source OVLs.
+This is handy for debugging and investigations related to create containers
+(the scratch one and the target userspace container).