Restore bazel mod deps in post-submit config. (#2304)

This change is a partial revert of
2c23d7c to fix breakages such as
https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/4676.

Progress towards
#2272.

Author: fweikert

buildkite/README.md

@@ -492,7 +492,7 @@ Example usage:
 ---
 matrix:
   bazel_version: ["4.2.2", "5.0.0"]
-  unix_platform: ["centos7", "debian10", "macos", "ubuntu2004"]
+  unix_platform: ["rockylinux8", "debian10", "macos", "ubuntu2004"]
   python: ["python2", "python3"]
   unix_compiler: ["gcc", "clang"]
   win_compiler: ["msvc", "clang"]

pipelines/bazel-postsubmit.patch

@@ -5,7 +5,7 @@
 +# Update this file by running ./update-bazel-postsubmit.sh under the same directory
 
  tasks:
-   centos7:
+   rockylinux8:
      shell_commands:
        - rm -rf $HOME/bazeltest
        - mkdir $HOME/bazeltest

pipelines/bazel-postsubmit.yml

@@ -6,6 +6,7 @@ tasks:
     shell_commands:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-linux"
     build_targets:
@@ -46,6 +47,7 @@ tasks:
     shell_commands:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-linux"
     build_targets:
@@ -59,6 +61,7 @@ tasks:
     shell_commands:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-linux"
     build_targets:
@@ -93,6 +96,7 @@ tasks:
     shell_commands:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-linux"
     build_targets:
@@ -111,6 +115,7 @@ tasks:
     shell_commands:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-linux"
     build_targets:
@@ -142,6 +147,7 @@ tasks:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
       - ln -sf $OUTPUT_BASE/external $HOME/bazeltest/external
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-macos"
     build_targets:
@@ -185,6 +191,7 @@ tasks:
       - rm -rf $HOME/bazeltest
       - mkdir $HOME/bazeltest
       - ln -sf $OUTPUT_BASE/external $HOME/bazeltest/external
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-macos"
     build_targets:
@@ -218,6 +225,7 @@ tasks:
     setup:
       - mkdir C:\b
       - mklink /J C:\b\bazeltest_external %OUTPUT_BASE:/=\%\external
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-windows"
     build_targets:
@@ -267,6 +275,7 @@ tasks:
     setup:
       - mkdir C:\b
       - mklink /J C:\b\bazeltest_external %OUTPUT_BASE:/=\%\external
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=ci-windows"
       - "--config=windows_arm64"
@@ -278,6 +287,8 @@ tasks:
   rbe_ubuntu2004:
     platform: ubuntu2004
     name: "RBE"
+    shell_commands:
+      - bazel mod deps --lockfile_mode=update
     build_flags:
       - "--config=remote"
       - "--remote_executor=grpcs://remotebuildexecution.googleapis.com"