[bazel] Drop WORKSPACE support (open-telemetry#3699)

Bazel 7.x (the current minimum supported version) supports using this
repo with bzlmod. With bazel 9.x coming out next month, it doesn't
support WORKSPACE anymore. It's getting quite hard to support both of
these versions at once as many rules repos no longer test WORKSPACE
support.

Author: keith

.github/workflows/ci.yml

@@ -735,32 +735,6 @@ jobs:
     - name: run tests
       run: ./ci/do_ci.sh bazel.test
 
-  bazel_no_bzlmod_test:
-    name: Bazel without bzlmod
-    runs-on: ubuntu-latest
-    steps:
-    - name: Harden the runner (Audit all outbound calls)
-      uses: step-security/harden-runner@f4a75cfd619ee5ce8d5b864b0d183aff3c69b55a # v2.13.1
-      with:
-        egress-policy: audit
-
-    - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
-      with:
-        submodules: 'recursive'
-    - name: Mount Bazel Cache
-      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
-      env:
-        cache-name: bazel_cache
-      with:
-        path: /home/runner/.cache/bazel
-        key: bazel_test
-    - name: setup
-      run: |
-        sudo ./ci/setup_ci_environment.sh
-        sudo ./ci/install_bazelisk.sh
-    - name: run tests
-      run: ./ci/do_ci.sh bazel.no_bzlmod.test
-
   bazel_test_async:
     name: Bazel with async export
     runs-on: ubuntu-latest

INSTALL.md

@@ -336,38 +336,10 @@ Bazel](https://docs.bazel.build/versions/3.7.0/install.html) guide.
 
 ### Incorporating into an existing Bazel Project
 
-- WORKSPACE file:
-
-```console
-http_archive(
-    name = "io_opentelemetry_cpp",
-    sha256 = "<sha256>",
-    strip_prefix = "opentelemetry-cpp-1.0.1",
-    urls = [
-        "https://github.com/open-telemetry/opentelemetry-cpp/archive/refs/tags/v1.0.1.tar.gz"
-    ],
-)
-
-# Load OpenTelemetry dependencies after load.
-load("@io_opentelemetry_cpp//bazel:repository.bzl", "opentelemetry_cpp_deps")
-
-opentelemetry_cpp_deps()
-
-# (required after v1.8.0) Load extra dependencies required for OpenTelemetry
-load("@io_opentelemetry_cpp//bazel:extra_deps.bzl", "opentelemetry_extra_deps")
-
-opentelemetry_extra_deps()
-
-# Load gRPC dependencies after load.
-load("@com_github_grpc_grpc//bazel:grpc_deps.bzl", "grpc_deps")
-
-grpc_deps()
-
-# Load extra gRPC dependencies due to https://github.com/grpc/grpc/issues/20511
-load("@com_github_grpc_grpc//bazel:grpc_extra_deps.bzl", "grpc_extra_deps")
-
-grpc_extra_deps()
+- MODULE.bazel file:
 
+```bzl
+bazel_dep(name = "opentelemetry-cpp", version = "<VERSION>", repo_name = "io_opentelemetry_cpp")
 ```
 
 - Component level BUILD file:

WORKSPACE

@@ -545,13 +545,6 @@ EOF
   make load_plugin_example
   examples/plugin/load/load_plugin_example ${PLUGIN_DIR}/libexample_plugin.so /dev/null
   exit 0
-elif [[ "$1" == "bazel.no_bzlmod.test" ]]; then
-  # Rapidyaml 0.9.0 as is does not support bazel,
-  # modules in bazel central repository required
-  # to build configuration.
-  bazel $BAZEL_STARTUP_OPTIONS build --enable_bzlmod=false $BAZEL_OPTIONS -- //... -//examples/configuration/... -//sdk/src/configuration/... -//sdk/test/configuration/...
-  bazel $BAZEL_STARTUP_OPTIONS test --enable_bzlmod=false $BAZEL_TEST_OPTIONS -- //... -//examples/configuration/... -//sdk/src/configuration/... -//sdk/test/configuration/...
-  exit 0
 elif [[ "$1" == "bazel.test" ]]; then
   bazel $BAZEL_STARTUP_OPTIONS build $BAZEL_OPTIONS $BAZEL_WITH_PREVIEW //...
   bazel $BAZEL_STARTUP_OPTIONS test $BAZEL_TEST_OPTIONS $BAZEL_WITH_PREVIEW //...