Fix spotlight config test assertion (#18196)

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Fixes a test failure where `process.env.SENTRY_SPOTLIGHT` was not
cleaned up after a test, causing environment variable pollution for
subsequent tests.

The failing test expected `spotlight: true` to resolve to `true`, but
due to the lingering environment variable, it received the URL from
`SENTRY_SPOTLIGHT` instead.

This PR adds an `afterEach` hook to the `spotlight configuration`
describe block to ensure `process.env.SENTRY_SPOTLIGHT` is deleted after
each test, preventing cross-test contamination.

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Co-authored-by: Cursor Agent <cursoragent@cursor.com>

Author: BYK

packages/node-core/test/sdk/init.test.ts

@@ -218,6 +218,10 @@ describe('init()', () => {
     });
 
     describe('spotlight configuration', () => {
+      afterEach(() => {
+        delete process.env.SENTRY_SPOTLIGHT;
+      });
+
       it('enables spotlight with default URL from `SENTRY_SPOTLIGHT` env variable (truthy value)', () => {
         process.env.SENTRY_SPOTLIGHT = 'true';