all: remove build restrictions requiring go1.18

govulncheck's go.mod file explicitly requires go1.21 and it can analyze
binaries built before go1.18. There is no need to have these build
restrictions.

Change-Id: I50a80da2490fd4bd8fb3d5b7a68f8796ff3ffe18
Reviewed-on: https://go-review.googlesource.com/c/vuln/+/597575
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Maceo Thompson <maceothompson@google.com>

cmd/govulncheck/main_test.go

diff --git a/cmd/govulncheck/main_test.go b/cmd/govulncheck/main_test.go
index c02a448..21b6d21 100644
--- a/cmd/govulncheck/main_test.go
+++ b/cmd/govulncheck/main_test.go
@@ -2,12 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Only run this on Go 1.18 or higher, because govulncheck can't
-// run on binaries before 1.18.
-
-//go:build go1.18
-// +build go1.18
-
 package main
 
 import (

internal/scan/binary.go

diff --git a/internal/scan/binary.go b/internal/scan/binary.go
index 56121a8..d28c356 100644
--- a/internal/scan/binary.go
+++ b/internal/scan/binary.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.18
-// +build go1.18
-
 package scan
 
 import (

internal/scan/extract.go

diff --git a/internal/scan/extract.go b/internal/scan/extract.go
index 30ee098..58a3f67 100644
--- a/internal/scan/extract.go
+++ b/internal/scan/extract.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.18
-// +build go1.18
-
 package scan
 
 import (

internal/vulncheck/binary.go

diff --git a/internal/vulncheck/binary.go b/internal/vulncheck/binary.go
index ca20f44..db96ba3 100644
--- a/internal/vulncheck/binary.go
+++ b/internal/vulncheck/binary.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.18
-// +build go1.18
-
 package vulncheck
 
 import (

internal/vulncheck/binary_test.go

diff --git a/internal/vulncheck/binary_test.go b/internal/vulncheck/binary_test.go
index 02e70a9..ab7a38d 100644
--- a/internal/vulncheck/binary_test.go
+++ b/internal/vulncheck/binary_test.go
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.18
-// +build go1.18
-
 package vulncheck
 
 import (

internal/vulncheck/doc.go

diff --git a/internal/vulncheck/doc.go b/internal/vulncheck/doc.go
index 3f19e29..e56cdfb 100644
--- a/internal/vulncheck/doc.go
+++ b/internal/vulncheck/doc.go
@@ -24,8 +24,7 @@
 
 [Source] accepts a list of [Package] objects, which
 are a trimmed version of [golang.org/x/tools/go/packages.Package] objects to
-reduce memory consumption. [Binary] accepts a path to a Go binary file that
-must have been compiled with Go 1.18 or greater.
+reduce memory consumption. [Binary] accepts a path to a Go binary file.
 
 Both [Source] and [Binary] require information about known
 vulnerabilities in the form of a vulnerability database,