chore: remove unused test files from repository root (#19150)

Remove orphaned test files that are not referenced in any tests or code:
- flux2_test_image.png
- test_generic_guardrail_config.yaml
- test_image_edit.png (root only, tests/image_gen_tests/ copy preserved)
- document.txt
- batch_small.jsonl (root and tests/batches_tests/)

batch_small.jsonl

@@ -1,4 +0,0 @@
-{"custom_id": "request-1", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Hello, how are you?"}]}}
-{"custom_id": "request-2", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "What is the weather today?"}]}}
-{"custom_id": "request-3", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Tell me a short joke"}]}}
-

document.txt

@@ -1,19 +0,0 @@
-LiteLLM provides a unified interface for calling 100+ different LLM providers.
-
-Key capabilities:
-- Translate requests to provider-specific formats
-- Consistent OpenAI-compatible responses
-- Retry and fallback logic across deployments
-- Proxy server with authentication and rate limiting
-- Support for streaming, function calling, and embeddings
-
-Popular providers supported:
-- OpenAI (GPT-4, GPT-3.5)
-- Anthropic (Claude)
-- AWS Bedrock
-- Azure OpenAI
-- Google Vertex AI
-- Cohere
-- And 95+ more
-
-This allows developers to easily switch between providers without code changes.

test_generic_guardrail_config.yaml

@@ -1,29 +0,0 @@
-model_list:
-  - model_name: gpt-4
-    litellm_params:
-      model: openai/gpt-4
-      api_key: os.environ/OPENAI_API_KEY
-
-  - model_name: gpt-4o
-    litellm_params:
-      model: openai/gpt-4o
-      api_key: os.environ/OPENAI_API_KEY
-
-  - model_name: gpt-3.5-turbo
-    litellm_params:
-      model: openai/gpt-3.5-turbo
-      api_key: os.environ/OPENAI_API_KEY
-
-guardrails:
-  - guardrail_name: thisispillar
-    litellm_params:
-      guardrail: generic_guardrail_api
-      mode: [pre_call, post_call]
-      api_base: os.environ/PILLAR_API_BASE
-      api_key: os.environ/PILLAR_API_KEY
-      default_on: true
-      additional_provider_specific_params:
-        plr_evidence: true
-
-general_settings:
-  master_key: sk-1234

tests/batches_tests/batch_small.jsonl

@@ -1,14 +0,0 @@
-{"custom_id": "request-1", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Hello, how are you?"}]}}
-{"custom_id": "request-2", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "What is the weather today?"}]}}
-{"custom_id": "request-3", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Tell me a short joke"}]}}
-{"custom_id": "request-1", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Hello, how are you?"}]}}
-{"custom_id": "request-2", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "What is the weather today?"}]}}
-{"custom_id": "request-3", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Tell me a short joke"}]}}
-{"custom_id": "request-1", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Hello, how are you?"}]}}
-{"custom_id": "request-2", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "What is the weather today?"}]}}
-{"custom_id": "request-3", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Tell me a short joke"}]}}
-{"custom_id": "request-1", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Hello, how are you?"}]}}
-{"custom_id": "request-2", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "What is the weather today?"}]}}
-{"custom_id": "request-3", "method": "POST", "url": "/v1/chat/completions", "body": {"model": "gpt-3.5-turbo", "messages": [{"role": "user", "content": "Tell me a short joke"}]}}
-
-