test(integration): ignore ambient forced color

[cyncui]

why

CLICOLOR_FORCE=true adds ansi escapes to clap's error output. the zero-runs integration test then fails because it expects plain text. fixes #1001.

what changed

• remove CLICOLOR_FORCE from the environment of integration test commands.

scope

• covers the test command helper. cli color behavior stays the same.

blast radius

all integration tests use this helper, so they no longer inherit this one terminal preference from the machine that runs them.

verification

• reproduced the failure with CLICOLOR_FORCE=true and NO_COLOR unset. the integration suite passed all 58 tests after the change.
• ran the full test suite, cargo fmt -- --check, and clippy with warnings denied.
• confirmed that the built cli still emits ansi color when CLICOLOR_FORCE=true.