fix: skip go.mod report inside autogenerated_exclude processor

[ldez]

before

$ golangci-lint run --enable-only gomoddirectives
WARN [runner] Can't process result by autogenerated_exclude processor: can't filter issue result.Issue{FromLinter:"gomoddirectives", Text:"local replacement are not allowed: k8s.io/api", Severity:"", SourceLines:[]string(nil), Replacement:(*result.Replacement)(nil), Pkg:(*packages.Package)(0xc000ed0480), LineRange:(*result.Range)(nil), Pos:token.Position{Filename:"go.mod", Offset:0, Line:240, Column:2}, HunkPos:0, ExpectNoLint:false, ExpectedNoLintLinter:""}: failed to get doc (lax) of file go.mod: failed to parse file: go.mod:7:1: expected 'package', found module 

With the PR

$ ./golangci-lint run --enable-only gomoddirectives
go.mod:240:2: local replacement are not allowed: k8s.io/api (gomoddirectives)
        k8s.io/api => ./staging/src/k8s.io/api
        ^
go.mod:241:2: local replacement are not allowed: k8s.io/apiextensions-apiserver (gomoddirectives)
        k8s.io/apiextensions-apiserver => ./staging/src/k8s.io/apiextensions-apiserver
        ^
go.mod:242:2: local replacement are not allowed: k8s.io/apimachinery (gomoddirectives)
        k8s.io/apimachinery => ./staging/src/k8s.io/apimachinery
        ^
...

The previous samples are created by analyzing the k8s code.