policy: replace golang/snappy with klauspost/compress/snappy

The golang/snappy implementation has been archived and is no longer
maintained. The github.com/klauspost/compress module provides
a maintained implementation, which is a drop-in replacement;
https://pkg.go.dev/github.com/klauspost/compress/snappy

> This is a drop-in replacement for github.com/golang/snappy.

Given that we're already depending on that module, we can switch
to the maintained implementation.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

go.mod

@@ -21,13 +21,13 @@ require (
 	github.com/docker/docker v28.5.2+incompatible
 	github.com/docker/go-units v0.5.0
 	github.com/gofrs/flock v0.13.0
-	github.com/golang/snappy v1.0.0
 	github.com/google/go-dap v0.12.1-0.20250904181021-d7a2259b058b
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/google/uuid v1.6.0
 	github.com/hashicorp/go-cty-funcs v0.0.0-20250818135842-6aab67130928
 	github.com/hashicorp/hcl/v2 v2.24.0
 	github.com/in-toto/in-toto-golang v0.10.0
+	github.com/klauspost/compress v1.18.5
 	github.com/mitchellh/hashstructure/v2 v2.0.2
 	github.com/moby/buildkit v0.29.0-rc1
 	github.com/moby/go-archive v0.2.0
@@ -155,7 +155,6 @@ require (
 	github.com/in-toto/attestation v1.1.2 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/klauspost/compress v1.18.5 // indirect
 	github.com/lestrrat-go/blackmagic v1.0.4 // indirect
 	github.com/lestrrat-go/dsig v1.0.0 // indirect
 	github.com/lestrrat-go/dsig-secp256k1 v1.0.0 // indirect

go.sum

@@ -289,8 +289,6 @@ github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 h1:f+oWsMOmNPc8J
 github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8/go.mod h1:wcDNUvekVysuuOpQKo3191zZyTpiI6se1N1ULghS0sw=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
-github.com/golang/snappy v1.0.0 h1:Oy607GVXHs7RtbggtPBnr2RmDArIsAefDwvrdWvRhGs=
-github.com/golang/snappy v1.0.0/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/certificate-transparency-go v1.3.2 h1:9ahSNZF2o7SYMaKaXhAumVEzXB2QaayzII9C8rv7v+A=
 github.com/google/certificate-transparency-go v1.3.2/go.mod h1:H5FpMUaGa5Ab2+KCYsxg6sELw3Flkl7pGZzWdBoYLXs=
 github.com/google/flatbuffers v25.2.10+incompatible h1:F3vclr7C3HpB1k9mxCGRMXq6FdUalZ6H/pNX4FP1v0Q=

policy/funcs.go

@@ -11,8 +11,8 @@ import (
 	"strings"
 
 	"github.com/distribution/reference"
-	"github.com/golang/snappy"
 	slsa1 "github.com/in-toto/in-toto-golang/in_toto/slsa_provenance/v1"
+	"github.com/klauspost/compress/snappy"
 	"github.com/moby/buildkit/client/llb"
 	gwclient "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/solver/pb"