fix: use copyFileSync from node

[trivikr]

Issue #, if available:
Fixes: #1312

Description of changes:
use copyFileSync from node instead of fs-extra

• fs.copyFileSync docs in node: https://nodejs.org/api/fs.html#fs_fs_copyfilesync_src_dest_mode
• the API was added in v8.5.0, and we use Node.js 10+ for generating clients
• copyFileSync from fs-extra uses native node implementation Add native fs.copyFile and fs.copyFileSync to copy() and copySync() jprichardson/node-fs-extra#505

Verified that yarn generate-clients succeeds to fix the bug:

$ yarn generate-clients -m ~/Downloads/temp
yarn run v1.22.4
$ node ./scripts/generate-clients -m /home/trivikr/Downloads/temp
preparing models from /home/trivikr/Downloads/temp...
copying model s3.2006-03-01.json...

...

child process exited with code 0
copying @aws-sdk/client-s3 from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/sdk-codegen/build/smithyprojections/sdk-codegen/s3.2006-03-01/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/clients
copying @aws-sdk/aws-ec2 from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/protocol-test-codegen/build/smithyprojections/protocol-test-codegen/aws-ec2/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/protocol_tests
copying @aws-sdk/aws-json from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/protocol-test-codegen/build/smithyprojections/protocol-test-codegen/aws-json/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/protocol_tests
copying @aws-sdk/aws-query from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/protocol-test-codegen/build/smithyprojections/protocol-test-codegen/aws-query/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/protocol_tests
copying @aws-sdk/aws-restjson from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/protocol-test-codegen/build/smithyprojections/protocol-test-codegen/aws-restjson/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/protocol_tests
copying @aws-sdk/aws-restxml from /local/home/trivikr/workspace/aws-sdk-js-v3/codegen/protocol-test-codegen/build/smithyprojections/protocol-test-codegen/aws-restxml/typescript-codegen to /local/home/trivikr/workspace/aws-sdk-js-v3/protocol_tests
Done in 13.43s.

generate-clients also succeed in other cases:

• yarn generate-clients
• yarn generate-clients -g codegen/sdk-codegen/aws-models/s3.2006-03-01.json

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and link to relevant comments in this thread.