[Infra] Remove workflows that require API keys or external services

These test suites are not pure unit tests and don't belong in Phase 1:
- litellm_utils_tests: health check tests need OPENAI_API_KEY
- pass_through_unit_tests: tests hit real Anthropic API
- router_unit_tests: tests call real OpenAI moderation endpoints
- proxy_security_tests: requires DATABASE_URL (Postgres)
- documentation_tests: requires docs directory at specific relative path

These will be re-added in later phases with proper secret scoping.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/test-unit-documentation.yml

@@ -1,20 +0,0 @@
-name: "Unit Tests: Documentation Validation"
-
-on:
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  documentation:
-    uses: ./.github/workflows/_test-unit-base.yml
-    with:
-      test-path: "tests/documentation_tests"
-      workers: 2
-      reruns: 1

.github/workflows/test-unit-litellm-utils.yml

@@ -1,20 +0,0 @@
-name: "Unit Tests: LiteLLM Utilities"
-
-on:
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  litellm-utils:
-    uses: ./.github/workflows/_test-unit-base.yml
-    with:
-      test-path: "tests/litellm_utils_tests"
-      workers: 2
-      reruns: 2

.github/workflows/test-unit-pass-through.yml

@@ -1,20 +0,0 @@
-name: "Unit Tests: Pass-Through Endpoints"
-
-on:
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  pass-through:
-    uses: ./.github/workflows/_test-unit-base.yml
-    with:
-      test-path: "tests/pass_through_unit_tests"
-      workers: 4
-      reruns: 2

.github/workflows/test-unit-router.yml

@@ -1,20 +0,0 @@
-name: "Unit Tests: Router"
-
-on:
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  router:
-    uses: ./.github/workflows/_test-unit-base.yml
-    with:
-      test-path: "tests/router_unit_tests"
-      workers: 4
-      reruns: 2

.github/workflows/test-unit-security.yml

@@ -1,20 +0,0 @@
-name: "Unit Tests: Security"
-
-on:
-  pull_request:
-    branches: [main]
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  security:
-    uses: ./.github/workflows/_test-unit-base.yml
-    with:
-      test-path: "tests/proxy_security_tests"
-      workers: 1
-      reruns: 1