Add dotnet 6 to be more conservative

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
LivingDocumentation.Abstractions	100%	100%	6	✔
LivingDocumentation.Analyzer	68%	60%	260	➖
LivingDocumentation.Descriptions	98%	97%	268	✔
LivingDocumentation.Extensions	100%	100%	22	✔
LivingDocumentation.Json	100%	75%	14	✔
LivingDocumentation.RenderExtensions	68%	80%	133	➖
LivingDocumentation.Statements	100%	100%	16	✔
Summary	81% (698 / 866)	77% (448 / 580)	719	✔

[coveralls]

Pull Request Test Coverage Report for Build 4097254544

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 79.253%

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Totals
Change from base Build 4006787555:	0.0%
Covered Lines:	698
Relevant Lines:	866

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 4097255862

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 79.253%

---

Totals
Change from base Build 4006787555:	0.0%
Covered Lines:	698
Relevant Lines:	866

---

💛 - Coveralls