feat: add type and variable aliases for os/exec compatibility

[k1LoW]

This pull request introduces type and variable aliases for several types and variables from the os/exec package, making them accessible under the current package. This change improves code clarity and allows consumers of this package to use these types and variables directly, without importing os/exec.

Type and variable aliasing:

• Added type aliases for exec.Cmd, exec.Error, and exec.ExitError as Cmd, Error, and ExitError, respectively.
• Added variable aliases for exec.ErrDot, exec.ErrNotFound, and exec.ErrWaitDelay as ErrDot, ErrNotFound, and ErrWaitDelay, respectively.

[github-actions]

Code Metrics Report

	main (20dd7a0)	#14 (3004d7b)	+/-
Coverage	89.1%	89.1%	0.0%
Code to Test Ratio	1:2.0	1:1.9	-0.2
Test Execution Time	41s	42s	+1s

Details

  |                     | main (20dd7a0) | #14 (3004d7b) | +/-  |
  |---------------------|----------------|---------------|------|
  | Coverage            |          89.1% |         89.1% | 0.0% |
  |   Files             |              2 |             2 |    0 |
  |   Lines             |             37 |            37 |    0 |
  |   Covered           |             33 |            33 |    0 |
- | Code to Test Ratio  |          1:2.0 |         1:1.9 | -0.2 |
  |   Code              |            169 |           178 |   +9 |
  |   Test              |            352 |           352 |    0 |
- | Test Execution Time |            41s |           42s |  +1s |

Code coverage of files in pull request scope (83.3% → 83.3%)

Files	Coverage	+/-	Status
exec.go	83.3%	0.0%	modified

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Reported by octocov