fix: installing vcpkg in custom image

[ChristopherHX]

I copied the fix from runner-images repo, let's see if it builds again.

[github-actions[bot]]

MegaLinter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ BASH	bash-exec	1		0	0.01s
✅ BASH	shellcheck	1		0	0.02s
✅ BASH	shfmt	1		0	0.01s
✅ CREDENTIALS	secretlint	yes		no	0.83s
✅ EDITORCONFIG	editorconfig-checker	1		0	0.01s
✅ GIT	git_diff	yes		no	0.01s
✅ SPELL	misspell	1		0	0.04s

See errors details in artifact MegaLinter reports on CI Job page _Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff_