Modernize workflows

[withinfocus]

Moves to an easier-to-maintain pattern and what I use elsewhere.

[github-actions]

✅MegaLinter analysis: Success

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
✅ ACTION	actionlint	2		0	0	0.29s
✅ COPYPASTE	jscpd	yes		no	no	1.46s
✅ EDITORCONFIG	editorconfig-checker	2		0	0	0.25s
✅ REPOSITORY	checkov	yes		no	no	11.65s
✅ REPOSITORY	gitleaks	yes		no	no	0.83s
✅ REPOSITORY	git_diff	yes		no	no	0.01s
✅ REPOSITORY	grype	yes		no	no	27.28s
✅ REPOSITORY	secretlint	yes		no	no	0.48s
✅ REPOSITORY	syft	yes		no	no	0.96s
✅ REPOSITORY	trivy	yes		no	no	7.28s
✅ REPOSITORY	trivy-sbom	yes		no	no	0.11s
✅ REPOSITORY	trufflehog	yes		no	no	2.13s
✅ SPELL	lychee	2		0	0	0.31s
✅ YAML	prettier	2	0	0	0	0.45s
✅ YAML	yamllint	2		0	0	0.36s

See detailed reports in MegaLinter artifacts
Set VALIDATE_ALL_CODEBASE: true in mega-linter.yml to validate all sources, not only the diff