chore: update headerforwarder (mesh-sdk-go) to v0.8.7

[potterbm-cb]

Motivation

A newer release of mesh-sdk-go provides more features, in particular some improvements to outgoing headers.

Solution

In order to keep header management simpler, this PR removes some of the context management to make go-ethereum add headers to requests. Instead, the HeaderForwarder http.RoundTripper will do the work of managing outgoing headers to native nodes as well as incoming headers.

[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

[marklandgrebe-cb]

lgtm