feat: publish flex docker image

[richardapeters]

No description provided.

[github-actions]

🦙 MegaLinter status: ⚠️ WARNING

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ ACTION	actionlint	5		0	0.01s
✅ DOCKERFILE	hadolint	1		0	0.11s
✅ JSON	prettier	6	1	0	0.69s
✅ JSON	v8r	6		0	3.56s
⚠️ MARKDOWN	markdownlint	8	1	3	0.82s
⚠️ MARKDOWN	markdown-link-check	8		7	3.07s
✅ MARKDOWN	markdown-table-formatter	8	1	0	0.45s
✅ REPOSITORY	checkov	yes		no	14.33s
✅ REPOSITORY	git_diff	yes		no	0.09s
✅ REPOSITORY	grype	yes		no	8.72s
✅ REPOSITORY	secretlint	yes		no	1.29s
✅ REPOSITORY	trivy	yes		no	5.78s
✅ REPOSITORY	trivy-sbom	yes		no	0.06s
✅ REPOSITORY	trufflehog	yes		no	2.29s
⚠️ SPELL	lychee	37		10	0.72s
✅ YAML	prettier	9	0	0	0.71s
✅ YAML	v8r	9		0	6.23s
✅ YAML	yamllint	9		0	0.39s

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