Clear agent environment variables in acceptance tests (#4344)

## Changes

Agent detection environment variables (`CLAUDECODE`, `GEMINI_CLI`,
`CURSOR_AGENT`) were causing the `User-Agent` header to include agent
information in acceptance test output. This made tests fail when run
from within Claude Code or other agent environments.

Moved the agent environment variable clearing from the bundle-specific
test.toml to the root test.toml so it applies to all tests globally.

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: pietern

acceptance/bundle/user_agent/test.toml

@@ -4,7 +4,3 @@ IncludeRequestHeaders = ["User-Agent"]
 
 [Env]
 DATABRICKS_CACHE_ENABLED = 'false'
-# Clear agent env vars to prevent them from affecting test output
-CLAUDECODE = ''
-GEMINI_CLI = ''
-CURSOR_AGENT = ''

acceptance/test.toml

@@ -17,6 +17,11 @@ Env.PYTHONDONTWRITEBYTECODE = "1"
 Env.PYTHONUNBUFFERED = "1"
 Env.PYTHONUTF8 = "1"
 
+# Clear agent env vars to prevent them from affecting test output
+Env.CLAUDECODE = ""
+Env.GEMINI_CLI = ""
+Env.CURSOR_AGENT = ""
+
 EnvMatrix.DATABRICKS_BUNDLE_ENGINE = ["terraform", "direct"]
 EnvMatrixExclude.noplantf = ["DATABRICKS_BUNDLE_ENGINE=terraform", "READPLAN=1"]
 EnvRepl.DATABRICKS_BUNDLE_ENGINE = false