docs: fix non working links to Service Providers

[gap-editor]

What changed? Why?
fix links to Slash, FailSafe, Runtime Verification, Dune, Hexens. previous ones were incorrect (without https://) so was working redirection to a file within the repository. on the documentation page (https://docs.base.org/base-services-hub) after clicking on one of the hyperlinks, the page was redirected to a page with the message 404 | The requested path could not be found
Notes to reviewers

How has it been tested?

Have you tested the following pages?

BaseWeb

• [] base.org
• [] base.org/names
• [] base.org/builders
• [] base.org/ecosystem
• [] base.org/name/jesse
• [] base.org/manage-names
• [] base.org/resources

BaseDocs

• docs.base.org
• [] docs sub-pages

[vercel]

@gap-editor is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[wbnns]

Thanks!