fix(functions): prevent redundant bind mounts on windows

[singh-inder]

What kind of change does this PR introduce?

Bug fix #4290

What is the new behavior?

Correctly split paths on windows. Didn't use ToDockerPath as it uses filepath.ToSlash internally

[coveralls]

Pull Request Test Coverage Report for Build 18433970309

Details

• 1 of 3 (33.33%) changed or added relevant lines in 1 file are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 54.67%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/functions/deploy/bundle.go	1	3	33.33%

Files with Coverage Reduction	New Missed Lines	%
internal/gen/keys/keys.go	5	12.9%

Totals
Change from base Build 18403671426:	-0.03%
Covered Lines:	6409
Relevant Lines:	11723

---

💛 - Coveralls

[sweatybridge]

Thank you for reporting and fixing this bug.