Embed files in membership-checker (GoogleCloudPlatform#7794)

* embed files in membership-checker

* change to embed the file as a string instead of a filesystem

.ci/containers/membership-checker/reviewer_assignment.go

@@ -4,6 +4,13 @@ import (
 	"fmt"
 	"net/http"
 	"strings"
+
+	_ "embed"
+)
+
+var (
+	//go:embed REVIEWER_ASSIGNMENT_COMMENT.md
+	reviewerAssignmentComment string
 )
 
 func requestReviewer(author, prNumber, GITHUB_TOKEN string) error {
@@ -153,12 +160,8 @@ func requestRandomReviewer(prNumber, GITHUB_TOKEN string) error {
 
 func postComment(prNumber, reviewer, GITHUB_TOKEN string) error {
 	url := fmt.Sprintf("https://api.github.com/repos/GoogleCloudPlatform/magic-modules/issues/%s/comments", prNumber)
-	comment, err := readFile(".ci/containers/membership-checker/REVIEWER_ASSIGNMENT_COMMENT.md")
-	if err != nil {
-		return err
-	}
 
-	comment = strings.Replace(comment, "{{reviewer}}", reviewer, 1)
+	comment := strings.Replace(reviewerAssignmentComment, "{{reviewer}}", reviewer, 1)
 
 	body := map[string]string{
 		"body": comment,

.ci/containers/membership-checker/utils.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"net/http"
 
 	"golang.org/x/exp/slices"
@@ -37,14 +36,6 @@ func requestCall(url, method, credentials string, result interface{}, body inter
 	return resp.StatusCode, nil
 }
 
-func readFile(filename string) (string, error) {
-	contents, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return "", err
-	}
-	return string(contents), nil
-}
-
 func removes(s1 []string, s2 []string) []string {
 	result := make([]string, 0, len(s1))