chore(librarian): cleanup footer value whitespace (#2526)

Fixes: #2524

Author: codyoss

internal/conventionalcommits/conventional_commits.go

@@ -360,6 +360,9 @@ func parseFooters(footerLines []string) (footers map[string]string, isBreaking b
 			isBreaking = true
 		}
 	}
+	for key, value := range footers {
+		footers[key] = strings.TrimSpace(value)
+	}
 	return footers, isBreaking
 }
 

internal/conventionalcommits/conventional_commits_test.go

@@ -761,7 +761,8 @@ func TestParseFooters(t *testing.T) {
 			name: "multi-line footers with key on one line, value on the next",
 			footerLines: []string{
 				"PiperOrigin-RevId: 123456",
-				"",
+				"Library-IDs:",
+				"library-one,library-two",
 				"Source-Link:",
 				"",
 				"googleapis/googleapis@a12b345",
@@ -772,8 +773,10 @@ func TestParseFooters(t *testing.T) {
 			},
 			wantFooters: map[string]string{
 				"PiperOrigin-RevId": "123456",
-				"Source-Link":       "\ngoogleapis/googleapis@a12b345",
-				"Copy-Tag":          "\neyJwIjoic"},
+				"Library-IDs":       "library-one,library-two",
+				"Source-Link":       "googleapis/googleapis@a12b345",
+				"Copy-Tag":          "eyJwIjoic",
+			},
 		},
 	} {
 		t.Run(test.name, func(t *testing.T) {