Activate CI servers reporters only if we find a related default env variable

[nvuillam]

Fixes #3317

[github-actions]

🦙 MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ BASH	bash-exec	5		0	0.01s
✅ BASH	shellcheck	5		0	0.13s
✅ BASH	shfmt	5	0	0	0.69s
✅ COPYPASTE	jscpd	yes		no	5.19s
✅ DOCKERFILE	hadolint	127		0	16.18s
✅ JSON	eslint-plugin-jsonc	23	0	0	4.74s
✅ JSON	jsonlint	21		0	0.29s
✅ JSON	v8r	23		0	25.7s
✅ MAKEFILE	checkmake	1		0	0.0s
⚠️ MARKDOWN	markdownlint	261	0	264	33.17s
✅ MARKDOWN	markdown-link-check	261		0	11.13s
✅ MARKDOWN	markdown-table-formatter	261	0	0	141.95s
✅ OPENAPI	spectral	1		0	1.52s
⚠️ PYTHON	bandit	208		64	2.9s
✅ PYTHON	black	208	0	0	5.27s
✅ PYTHON	flake8	208		0	1.62s
✅ PYTHON	isort	208	0	0	1.24s
✅ PYTHON	mypy	208		0	17.69s
✅ PYTHON	pylint	208		0	17.39s
⚠️ PYTHON	pyright	208		352	28.51s
✅ PYTHON	ruff	208	0	0	0.72s
✅ REPOSITORY	checkov	yes		no	40.78s
✅ REPOSITORY	git_diff	yes		no	0.56s
⚠️ REPOSITORY	grype	yes		1	24.61s
✅ REPOSITORY	secretlint	yes		no	18.3s
✅ REPOSITORY	trivy	yes		no	25.94s
✅ REPOSITORY	trivy-sbom	yes		no	13.03s
⚠️ REPOSITORY	trufflehog	yes		1	11.13s
✅ SPELL	cspell	683		0	28.55s
✅ SPELL	lychee	341		0	24.91s
✅ XML	xmllint	3	0	0	0.62s
✅ YAML	prettier	160	0	0	6.21s
✅ YAML	v8r	102		0	181.68s
✅ YAML	yamllint	161		0	2.33s

See detailed report in MegaLinter reports

MegaLinter is graciously provided by