Upgrade SAI version to 7.1.73.4 (#17698)

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

Signed-off-by: zitingguo-ms <zitingguo@microsoft.com>

platform/broadcom/sai.mk

@@ -1,5 +1,5 @@
-LIBSAIBCM_XGS_VERSION = 7.1.62.4
-LIBSAIBCM_DNX_VERSION = 7.1.66.4
+LIBSAIBCM_XGS_VERSION = 7.1.73.4
+LIBSAIBCM_DNX_VERSION = 7.1.73.4
 LIBSAIBCM_BRANCH_NAME = REL_7.0_202205
 LIBSAIBCM_XGS_URL_PREFIX = "https://sonicstorage.blob.core.windows.net/public/sai/bcmsai/$(LIBSAIBCM_BRANCH_NAME)/$(LIBSAIBCM_XGS_VERSION)"
 LIBSAIBCM_DNX_URL_PREFIX = "https://sonicstorage.blob.core.windows.net/public/sai/bcmsai/$(LIBSAIBCM_BRANCH_NAME)/$(LIBSAIBCM_DNX_VERSION)"