Update absl submodule and dep to latest 20230802.0 LTS (#13515)

Fixes https://github.com/protocolbuffers/protobuf/issues/13499

Needs to be backported to 24.x

Closes #13515

COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/13515 from zhangskz:update-absl 508f2912e3
PiperOrigin-RevId: 555679980

.gitmodules

@@ -5,7 +5,7 @@
 [submodule "third_party/abseil-cpp"]
 	path = third_party/abseil-cpp
 	url = https://github.com/abseil/abseil-cpp.git
-	branch = lts_2023_01_25
+	branch = lts_2023_08_02
 [submodule "third_party/jsoncpp"]
 	path = third_party/jsoncpp
 	url = https://github.com/open-source-parsers/jsoncpp.git

protobuf_deps.bzl

@@ -42,8 +42,8 @@ def protobuf_deps():
         _github_archive(
             name = "com_google_absl",
             repo = "https://github.com/abseil/abseil-cpp",
-            commit = "c2435f8342c2d0ed8101cb43adfd605fdc52dca2",  # Abseil LTS 20230125.3
-            sha256 = "ea1d31db00eb37e607bfda17ffac09064670ddf05da067944c4766f517876390",
+            commit = "29bf8085f3bf17b84d30e34b3d7ff8248fda404e",  # Abseil LTS 20230802
+            sha256 = "f4871f2982e29496f4ddd598ccd5a87fea42f23c49b5e5eb459d57eab91df9d9",
         )
 
     if not native.existing_rule("zlib"):