chore: update module github.com/google/go-github/v67 to v68

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/containerd/platforms v1.0.0-rc.1
 	github.com/emicklei/dot v1.6.4
 	github.com/google/go-github/v67 v67.0.0
+	github.com/google/go-github/v68 v68.0.0
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/moby/buildkit v0.19.0
 	github.com/moby/docker-image-spec v1.3.1

go.sum

@@ -64,6 +64,7 @@ github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-github/v67 v67.0.0 h1:g11NDAmfaBaCO8qYdI9fsmbaRipHNWRIU/2YGvlh4rg=
 github.com/google/go-github/v67 v67.0.0/go.mod h1:zH3K7BxjFndr9QSeFibx4lTKkYS3K9nDanoI1NjaOtY=
+github.com/google/go-github/v68 v68.0.0/go.mod h1:K9HAUBovM2sLwM408A18h+wd9vqdLOEqTUCbnRIcx68=
 github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=