feat: fix CI: fix TS18046 errors in catch blocks for strict mode compliance

[Copilot]

fix: #20

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[hsluoyz]

@copilot fix: https://github.com/casbin/casbin-core/actions/runs/21599498556/job/62241293474?pr=21

Run yarn run lint
  yarn run lint
  shell: /usr/bin/bash -e {0}
yarn run v1.22.22
$ eslint . --ext .js,.ts

/home/runner/work/casbin-core/casbin-core/src/util/util.ts
Error:   216:13  error  Replace `((b·as·any)·as·Array<any>).includes(a)·as·unknown)` with `b·as·any·as·Array<any>).includes(a)·as·unknown`  prettier/prettier
Error:   218:10  error  Replace `((a·in·(b·as·any))·as·unknown)` with `(a·in·(b·as·any))·as·unknown`                                        prettier/prettier

/home/runner/work/casbin-core/casbin-core/test/enforcer.test.ts
Error:   576:28  error  Replace `(98·as·unknown)` with `98·as·unknown`  prettier/prettier
Error:   577:28  error  Replace `(67·as·unknown)` with `67·as·unknown`  prettier/prettier
Error:   578:28  error  Replace `(34·as·unknown)` with `34·as·unknown`  prettier/prettier
Error:   648:28  error  Replace `(98·as·unknown)` with `98·as·unknown`  prettier/prettier
Error:   649:28  error  Replace `(67·as·unknown)` with `67·as·unknown`  prettier/prettier
Error:   650:28  error  Replace `(34·as·unknown)` with `34·as·unknown`  prettier/prettier

✖ 8 problems (8 errors, 0 warnings)
  8 errors and 0 warnings potentially fixable with the `--fix` option.

error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Error: Process completed with exit code 1.

[Copilot]

@copilot fix: https://github.com/casbin/casbin-core/actions/runs/21599498556/job/62241293474?pr=21

...

Fixed the prettier formatting issues by running yarn run fmt. The errors were pre-existing formatting issues in src/util/util.ts and test/enforcer.test.ts that have now been resolved. Commit: 6c8f5c2

[hsluoyz]

@copilot only run against Node.js 20 in CI, drop Node.js 18

[Copilot]

@copilot only run against Node.js 20 in CI, drop Node.js 18

Updated CI workflows to only run against Node.js 20. Removed Node.js 18 from the test matrix in both ci.yml and platform_test.yml. Commit: 3e1153c