chore(deps): update dependency protobuf to v6

Author: renovate-bot

.kokoro/requirements.txt

@@ -470,18 +470,16 @@ platformdirs==4.3.6 \
     --hash=sha256:357fb2acbc885b0419afd3ce3ed34564c13c9b95c89360cd9563f73aa5e2b907 \
     --hash=sha256:73e575e1408ab8103900836b97580d5307456908a03e92031bab39e4554cc3fb
     # via virtualenv
-protobuf==5.29.3 \
-    --hash=sha256:0a18ed4a24198528f2333802eb075e59dea9d679ab7a6c5efb017a59004d849f \
-    --hash=sha256:0eb32bfa5219fc8d4111803e9a690658aa2e6366384fd0851064b963b6d1f2a7 \
-    --hash=sha256:3ea51771449e1035f26069c4c7fd51fba990d07bc55ba80701c78f886bf9c888 \
-    --hash=sha256:5da0f41edaf117bde316404bad1a486cb4ededf8e4a54891296f648e8e076620 \
-    --hash=sha256:6ce8cc3389a20693bfde6c6562e03474c40851b44975c9b2bf6df7d8c4f864da \
-    --hash=sha256:84a57163a0ccef3f96e4b6a20516cedcf5bb3a95a657131c5c3ac62200d23252 \
-    --hash=sha256:a4fa6f80816a9a0678429e84973f2f98cbc218cca434abe8db2ad0bffc98503a \
-    --hash=sha256:a8434404bbf139aa9e1300dbf989667a83d42ddda9153d8ab76e0d5dcaca484e \
-    --hash=sha256:b89c115d877892a512f79a8114564fb435943b59067615894c3b13cd3e1fa107 \
-    --hash=sha256:c027e08a08be10b67c06bf2370b99c811c466398c357e615ca88c91c07f0910f \
-    --hash=sha256:daaf63f70f25e8689c072cfad4334ca0ac1d1e05a92fc15c54eb9cf23c3efd84
+protobuf==6.30.0 \
+    --hash=sha256:501810e0eba1d327e783fde47cc767a563b0f1c292f1a3546d4f2b8c3612d4d0 \
+    --hash=sha256:52d4bb6fe76005860e1d0b8bfa126f5c97c19cc82704961f60718f50be16942d \
+    --hash=sha256:7337d76d8efe65ee09ee566b47b5914c517190196f414e5418fa236dfd1aed3e \
+    --hash=sha256:7940ab4dfd60d514b2e1d3161549ea7aed5be37d53bafde16001ac470a3e202b \
+    --hash=sha256:852b675d276a7d028f660da075af1841c768618f76b90af771a8e2c29e6f5965 \
+    --hash=sha256:9b33d51cc95a7ec4f407004c8b744330b6911a37a782e2629c67e1e8ac41318f \
+    --hash=sha256:bb35ad251d222f03d6c4652c072dfee156be0ef9578373929c1a7ead2bd5492c \
+    --hash=sha256:d79bf6a202a536b192b7e8d295d7eece0c86fbd9b583d147faf8cfeff46bf598 \
+    --hash=sha256:e5ef216ea061b262b8994cb6b7d6637a4fb27b3fb4d8e216a6040c0b93bd10d7
     # via
     #   gcp-docuploader
     #   gcp-releasetool