Upgrade to Go 1.26.1

[anthr76]

Describe the bug

docker run --rm -it --entrypoint '' ghcr.io/oxsecurity/megalinter-go:beta go version
go version go1.25.8 linux/amd64

golang-ci lint is refusing to run due to the go version being out of date. While golangci-lint has been updated the underlying go version is out of date

To Reproduce

Have a go 1.26x project and run golangci-lint within megalinter.

Observe:

 level=error msg="Running error: context loading failed: failed to load packages: failed to load packages: failed to load with go/packages: err: exit status 1: stderr: go: go.mod requires go >= 1.26.1 (running go 1.25.8; GOTOOLCHAIN=local)\n"

Expected behavior
A clear and concise description of what you expected to happen.

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Additional context
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