fix: copyFiles to protected

[echosoar]

No description provided.

[codecov-io]

Codecov Report

Merging #86 into master will decrease coverage by 0.03%.
The diff coverage is 50%.

@@            Coverage Diff            @@
##           master     #86      +/-   ##
=========================================
- Coverage   76.73%   76.7%   -0.04%     
=========================================
  Files          71      71              
  Lines        2484    2485       +1     
  Branches      233     236       +3     
=========================================
  Hits         1906    1906              
- Misses        576     577       +1     
  Partials        2       2

Impacted Files	Coverage Δ
packages/serverless-invoke/src/core.ts	77% <100%> (ø)	⬆️
packages/faas-cli-command-core/src/core.ts	63.52% <42.85%> (-0.41%)	⬇️

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[echosoar]

• command-core性能优化
  From:

  Benchmark:
    core help no plugin  x 202,982 ops/sec ±0.88% (89 runs sampled)
    core help test plugin x 114,183 ops/sec ±1.03% (86 runs sampled)
    core invoke test plugin x 104,416 ops/sec ±1.26% (71 runs sampled)
  

  To:

  Benchmark:
    core help no plugin  x 304,842 ops/sec ±4.32% (72 runs sampled)
    core help test plugin x 144,904 ops/sec ±4.23% (77 runs sampled)
    core invoke test plugin x 134,072 ops/sec ±3.13% (75 runs sampled)
  

• command-core 单测覆盖率提升
• 移除 command-core deepMerge 依赖
• serverless-invoke copyFiles 设置为 protected，供子类继承调用