[202205] Upgrade SAI version to 7.1.73.4

[Gfrom2016]

Why I did it

Upgrade the SAI version to 7.1.73.4 to include the following fix:

• 7.1.67.4: [CSP CS00012302165] Backport JIRA SONIC-77116 to rel_ocp_sai_7_1
• 7.1.68.4: [CSP CS00012316299][SAI_BRANCH rel_ocp_sai_7_1] L3 entry delete failed when SER error is present
• 7.1.69.4: ECMP LB traffic polarization, configure hash_offset along with hash_seed attr
• 7.1.70.4: JIRA# SONIC-79944
• 7.1.71.4: SID: MMU cosq control configuration with Dynamic Type Check
• 7.1.72.4: BACKPORT SONIC-81858 PFCWD on IPv6 JIRA# SONIC-84146]SONIC-81858
• 7.1.73.4: [CSP CS00012322843] SAI_API_ROUTE:brcm_sai_xgs_route_create:115 iptnl info get failed with error -7

Work item tracking

• Microsoft ADO (number only): 26336177

How I did it

Upgrade xgs SAI version in sai.mk file.

How to verify it

Run basic SONiC test using SAI release pipeline, all cases passed.
https://dev.azure.com/mssonic/internal/_build/results?buildId=452376&view=results

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205
• 202211
• 202305

Tested branch (Please provide the tested image version)

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)