build: bump required language level to 1.24, compiler to 1.25 (#10248)

(After 2.0.1)

lib/api/api_test.go

@@ -888,7 +888,7 @@ func TestHtmlFormLogin(t *testing.T) {
 				t.Errorf("Unexpected non-200 return code %d at %s", resp.StatusCode, noAuthPath)
 			}
 			if hasSessionCookie(resp.Cookies()) {
-				t.Errorf("Unexpected session cookie at " + noAuthPath)
+				t.Errorf("Unexpected session cookie at %s", noAuthPath)
 			}
 		})
 	}

lib/ignore/ignore_test.go

@@ -1080,7 +1080,7 @@ func TestIssue4901(t *testing.T) {
 
 	fd, err := pats.fs.Create(".stignore")
 	if err != nil {
-		t.Fatalf(err.Error())
+		t.Fatal(err)
 	}
 	if _, err := fd.Write([]byte(stignore)); err != nil {
 		t.Fatal(err)
@@ -1102,7 +1102,7 @@ func TestIssue4901(t *testing.T) {
 
 	fd, err = pats.fs.Create("unicorn-lazor-death")
 	if err != nil {
-		t.Fatalf(err.Error())
+		t.Fatal(err)
 	}
 	if _, err := fd.Write([]byte(" ")); err != nil {
 		t.Fatal(err)