Avoid Dependabot rollup updates

[elchininet]

This pull request excludes rollup from Dependabot updates. After version 4.21.0 starting a server using start-server-and-test ends up in:

> [email protected] test:ci /home/runner/work/shadow-dom-selector/shadow-dom-selector
> pnpm clean && start-server-and-test 'pnpm demo' http://localhost:3000 'pnpm test:run'


> [email protected] clean /home/runner/work/shadow-dom-selector/shadow-dom-selector
> rm -rf dist .nyc_output coverage || true

1: starting server using command "pnpm demo"
and when url "[ 'http://localhost:3000' ]" is responding with HTTP status code 200
running tests using command "pnpm test:run"


> [email protected] demo /home/runner/work/shadow-dom-selector/shadow-dom-selector
> rollup --config rollup.test.config.js --bundleConfigAsCjs -w

Error: server closed unexpectedly
    at ChildProcess.onClose (/home/runner/work/shadow-dom-selector/shadow-dom-selector/node_modules/.pnpm/[email protected]/node_modules/start-server-and-test/src/index.js:[8](https://github.com/elchininet/shadow-dom-selector/actions/runs/10757386433/job/29831361013?pr=79#step:8:9)3:14)
    at ChildProcess.emit (node:events:517:28)
    at maybeClose (node:internal/child_process:10[9](https://github.com/elchininet/shadow-dom-selector/actions/runs/10757386433/job/29831361013?pr=79#step:8:10)8:16)
    at ChildProcess._handle.onexit (node:internal/child_process:303:5)
 ELIFECYCLE  Command failed with exit code 1.
Error: Process completed with exit code 1.

[coveralls]

coverage: 100.0%. remained the same
when pulling 3dddc5a on avoid_dependabot_rollup_updates
into a998b9f on master.