[envsec] use filecache from opensource/pkg (#177)

## Summary

Can remove the `internal/filecache` now that the `jetpack-io/pkg`
repository has it.

Also did:
```
go get -u go.jetpack.io/pkg
go mod tidy
```

## How was it tested?

compiles

Author: savil

envsec/go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/samber/lo v1.38.1
 	github.com/spf13/cobra v1.7.0
-	go.jetpack.io/pkg v0.0.0-20231002215645-9afeb0623fd3
+	go.jetpack.io/pkg v0.0.0-20231012130632-77dcd111db2e
 	go.jetpack.io/typeid v0.1.0
 	golang.org/x/oauth2 v0.12.0
 	golang.org/x/text v0.13.0

envsec/go.sum

@@ -106,8 +106,8 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-go.jetpack.io/pkg v0.0.0-20231002215645-9afeb0623fd3 h1:aMydtVCHn7dfotOyV41VAxX5b5OOsCc4TxOXwDt38Yw=
-go.jetpack.io/pkg v0.0.0-20231002215645-9afeb0623fd3/go.mod h1:iaf3e/aENp5luwYFlfCxj+GsiwqHagbvRAY3bIdEgGA=
+go.jetpack.io/pkg v0.0.0-20231012130632-77dcd111db2e h1:GtqFrE5uUf6rXFk3zaIqIfLfykrqrB8gp6bDmOfH+2s=
+go.jetpack.io/pkg v0.0.0-20231012130632-77dcd111db2e/go.mod h1:m49CAcLbpZttEbzoEWC1SKD+/z5mEiFdw0dQxY6AM5Q=
 go.jetpack.io/typeid v0.1.0 h1:suTmjNR3y2em2gCTG06agFfcACm3+zuxfziMUk5UXnw=
 go.jetpack.io/typeid v0.1.0/go.mod h1:E11ObFkKlvsSTxwwYIm+zpbsRthjIMDy/JGBogs2vSo=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=

envsec/internal/filecache/filecache.go

@@ -11,7 +11,7 @@ import (
 	"github.com/pkg/errors"
 	"go.jetpack.io/envsec"
 	"go.jetpack.io/envsec/internal/envvar"
-	"go.jetpack.io/envsec/internal/filecache"
+	"go.jetpack.io/pkg/filecache"
 	"go.jetpack.io/pkg/sandbox/auth/session"
 )
 
@@ -76,9 +76,11 @@ func (a *AWSFed) awsCreds(
 	idToken string,
 ) (*types.Credentials, error) {
 
-	svc := cognitoidentity.New(cognitoidentity.Options{
-		Region: a.Region,
-	})
+	svc := cognitoidentity.New(
+		cognitoidentity.Options{
+			Region: a.Region,
+		},
+	)
 
 	logins := map[string]string{
 		a.Provider: idToken,