Upgrade xgs SAI version to 8.4.46.0 (sonic-net#19298)

Why I did it
Upgrade the xgs SAI version to 8.4.46.0 to include the following changes:

8.4.42.0: Support _brcm_sai_port_unlos_set when external port_phy_addr is 0xff
8.4.45.0: Uplift SONIC-85239 patch-2 to 8.4.
8.4.46.0: [CSP CS00012343232][SAI_BRANCH rel_ocp_sai_8_4]Back port MMU related Fixes to 8.4 specific to LTSW/TH4
Work item tracking
Microsoft ADO (number only): 28384445
How I did it
Upgrade the SAI version in the sai.mk file.

How to verify it
Run the SONiC basic test in the SAI release pipeline, all passed:
https://dev.azure.com/mssonic/internal/_build/results?buildId=570531&view=results

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

platform/broadcom/sai.mk

@@ -1,6 +1,6 @@
-LIBSAIBCM_XGS_VERSION = 8.4.44.0
+LIBSAIBCM_XGS_VERSION = 8.4.46.0
 LIBSAIBCM_DNX_VERSION = 9.2.12.1
-LIBSAIBCM_XGS_BRANCH_NAME = SAI_8.4.0_GA_for_22_image
+LIBSAIBCM_XGS_BRANCH_NAME = SAI_8.4.0_GA
 LIBSAIBCM_DNX_BRANCH_NAME = SAI_9.2.0.3
 LIBSAIBCM_XGS_URL_PREFIX = "https://sonicstorage.blob.core.windows.net/public/sai/sai-broadcom/$(LIBSAIBCM_XGS_BRANCH_NAME)/$(LIBSAIBCM_XGS_VERSION)/xgs"
 LIBSAIBCM_DNX_URL_PREFIX = "https://sonicstorage.blob.core.windows.net/public/sai/sai-broadcom/$(LIBSAIBCM_DNX_BRANCH_NAME)/$(LIBSAIBCM_DNX_VERSION)/dnx"