infra: Fix bazel 8.0 WORKSPACE disable problem

[arthurscchan]

The base-builder depends on the google/fuzztest project to precompile the centipede module. The google/fuzztest uses the WORKSPACE approach to provide repository location. But since bazel 8 (released yesterday), the WORKSPACE approach is no longer enabled by default (https://bazel.build/versions/8.0.0/external/migration). Also, in the Dockerfile of the base-builder, we automatically install the latest version of bazel (which is bazel 8 from yesterday), that make the building of fuzztest and eventually the base-builder failed.

This PR fixes the problem temporary by forcing the installation of bazel version 7.4.0 to avoid the disabling of WORKSPACE defintion, this make the build of google/fuzztest success.

[DavidKorczynski]

/gcbrun trial_build.py --fuzzing-engines libfuzzer

[arthurscchan]

Remark:

This line in base-builder Docker file fails (https://github.com/google/oss-fuzz/blob/master/infra/base-images/base-builder/Dockerfile#L154) with the following errors.

ERROR: no such package '@@[unknown repo 'com_google_absl' requested from @@]//absl/strings': The repository '@@[unknown repo 'com_google_absl' requested from @@]' could not be resolved: No repository visible as '@com_google_absl' from main repository. Was the repository introduced in WORKSPACE? The WORKSPACE file is disabled by default in Bazel 8 (late 2024) and will be removed in Bazel 9 (late 2025), please migrate to Bzlmod. See https://bazel.build/external/migration
ERROR: /src/fuzztest/centipede/BUILD:169:11: no such package '@@[unknown repo 'com_google_absl' requested from @@]//absl/strings': The repository '@@[unknown repo 'com_google_absl' requested from @@]' could not be resolved: No repository visible as '@com_google_absl' from main repository. Was the repository introduced in WORKSPACE? The WORKSPACE file is disabled by default in Bazel 8 (late 2024) and will be removed in Bazel 9 (late 2025), please migrate to Bzlmod. See https://bazel.build/external/migration and referenced by '//centipede:config_file'
Target //centipede:test_util_sh up-to-date (nothing to build)
ERROR: Analysis of target '//centipede:config_file' failed; build aborted: Analysis failed

Because Bazel 8 is used from yesterday automatically and it does not enable WORKSPACE by default. Thus the project no longer can retrieve the correct repository for com_google_absl which is defined in WORKSPACE.

[DavidKorczynski]

/gcbrun trial_build.py all --fuzzing-engines libfuzzer

[arthurscchan]

superseded by #12840 with less intrusive approach.