This commit adds a new feature to the Jest runtime package that exposes
the `isTornDown` variable as a way to check if the Jest environment has
been torn down programmatically. The `isTornDown` variable is a
read-only boolean that is set to `true` when the environment is torn
down and `false` otherwise.

The commit also adds documentation for the `isTornDown` variable to the
Jest runtime module.

Closes jestjs#13640

This commit adds a new feature to the Jest runtime package that exposes
the `isTornDown` variable as a way to check if the Jest environment has
been torn down programmatically. The `isTornDown` variable is a
read-only boolean that is set to `true` when the environment is torn
down and `false` otherwise.

The commit also adds documentation for the `isTornDown` variable to the
Jest runtime module.

Closes jestjs#13640

…/jest into 13640-expose-isTornDown

# Conflicts:
#	packages/jest-environment/src/index.ts

…/jest into 13640-expose-isTornDown

# Conflicts:
#	packages/jest-environment/src/index.ts

…vironmentTornDown variable as a way to check if the Jest environment has been torndown

function, removed the word flag

Co-authored-by: Tom Mrazauskas <tom@mrazauskas.de>