add upgrade to firefox installation and refactor FirefoxKtTest

src/main/kotlin/org/domaindrivenarchitecture/provs/desktop/infrastructure/Firefox.kt

@@ -38,4 +38,5 @@ fun Prov.installFirefox() = task {
     )
 
     aptInstall("firefox")
+    cmd("apt upgrade -y firefox", sudo = true)
 }

src/test/kotlin/org/domaindrivenarchitecture/provs/desktop/infrastructure/FirefoxKtTest.kt

@@ -9,13 +9,15 @@ internal class FirefoxKtTest {
 
     @ExtensiveContainerTest
     fun installFirefox() {
+        defaultTestContainer().session {
             // when
-        val res = defaultTestContainer().installFirefox()
+            val res = installFirefox()
 
             // then
             assertTrue(res.success)
 
-        val ffIsInstalled = defaultTestContainer().isPackageInstalled("firefox")
+            val ffIsInstalled = isPackageInstalled("firefox")
             assertTrue(ffIsInstalled)
         }
     }
+}