sap_hana_preconfigure/SLES: Update azure override readme and conditional

Description:

Update readme, defaults and arguments file https://github.com/sap-linuxlab/community.sap_install/blob/c1b479ef710f0f0803a5a081eafd621465c86d4b/roles/sap_hana_preconfigure/README.md?plain=1#L429 with extra details:
```
If the variable is set, an override file for saptune will be created (/etc/saptune/override/2382421)
to set net.ipv4.tcp_timestamps,
net.ipv4.tcp_tw_reuse and net.ipv4.tcp_tw_recycle to 0.
```
Investigate possibility to add OS_MAJOR version switch as parameter net.ipv4.tcp_tw_recycle is no longer valid since SLES 15 GA. SLES 12 and older could use it, but they are no longer mentioned as supported versions.
```
Remove net.ipv4.tcp_tw_recycle from readme if it is removed from configuration
```
Remove old commented out code present in https://github.com/sap-linuxlab/community.sap_install/blob/c1b479ef710f0f0803a5a081eafd621465c86d4b/roles/sap_hana_preconfigure/tasks/SLES/assert-configuration.yml#L42 because it is already present in https://github.com/sap-linuxlab/community.sap_install/blob/c1b479ef710f0f0803a5a081eafd621465c86d4b/roles/sap_hana_preconfigure/tasks/SLES/configuration.yml#L94

sap-linuxlab / community.sap_install