Exclude symlinks when VALIDATE_ALL_CODEBASE = false

[nvuillam]

Fixes #2944

[github-actions]

🦙 MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ BASH	bash-exec	5		0	0.03s
✅ BASH	shellcheck	5		0	0.12s
✅ BASH	shfmt	5	0	0	0.46s
✅ COPYPASTE	jscpd	yes		no	3.79s
✅ DOCKERFILE	hadolint	123		0	19.84s
✅ JSON	eslint-plugin-jsonc	23	0	0	2.91s
✅ JSON	jsonlint	21		0	0.27s
✅ JSON	v8r	23		0	15.07s
✅ MAKEFILE	checkmake	1		0	0.0s
⚠️ MARKDOWN	markdownlint	255	0	255	45.75s
✅ MARKDOWN	markdown-link-check	255		0	6.63s
✅ MARKDOWN	markdown-table-formatter	255	0	0	37.43s
✅ OPENAPI	spectral	1		0	1.68s
⚠️ PYTHON	bandit	200		61	2.77s
✅ PYTHON	black	200	0	0	5.27s
✅ PYTHON	flake8	200		0	2.57s
✅ PYTHON	isort	200	0	0	0.97s
✅ PYTHON	mypy	200		0	12.21s
✅ PYTHON	pylint	200		0	15.04s
⚠️ PYTHON	pyright	200		337	24.98s
✅ PYTHON	ruff	200	0	0	0.55s
✅ REPOSITORY	checkov	yes		no	40.73s
✅ REPOSITORY	git_diff	yes		no	0.46s
⚠️ REPOSITORY	grype	yes		1	11.83s
✅ REPOSITORY	secretlint	yes		no	11.21s
✅ REPOSITORY	trivy	yes		no	30.36s
✅ REPOSITORY	trivy-sbom	yes		no	1.37s
✅ SPELL	cspell	665		0	29.7s
✅ SPELL	lychee	335		0	7.33s
✅ XML	xmllint	3	0	0	0.46s
✅ YAML	prettier	160	0	0	5.89s
✅ YAML	v8r	102		0	186.0s
✅ YAML	yamllint	161		0	1.81s

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