gnu: qtbase: Update to 6.8.3 and disable qthread test.

* gnu/packages/qt.scm (qtbase): Update to 6.8.3.
[#:phases] {check}: Skip tst_qthread.

Fixes: #2467
Change-Id: Ie2691f94f9e3d7ddb96be55d5026a0b08b2d8d1d

gnu/packages/qt.scm

@@ -761,13 +761,13 @@ developers using C++ or QML, a CSS & JavaScript like language.")
   (package
     (inherit qtbase-5)
     (name "qtbase")
-    (version "6.8.2")
+    (version "6.8.3")
     (source (origin
               (inherit (package-source qtbase-5))
               (uri (qt-url name version))
               (sha256
                (base32
-                "01gy1p8zvxq8771x6iqkrc7s3kzdddgf1i7xj656w7j1dp746801"))
+                "100bkvs320s9gim4j7l6wkrl1abz1mwbmwwrscir1fq1as81n02n"))
               (modules '((guix build utils)))
               (snippet
                ;; corelib uses bundled harfbuzz, md4, md5, sha3
@@ -1004,6 +1004,10 @@ tst_qt_cmake_create.cpp"
                        ;; The 'tst_qsqlthread' test sometimes fails.
                        "tst_qsqlthread"
 
+                       ;; The 'tst_qthread' test is also flaky, despite the
+                       ;; patch applied that promised to fix it.
+                       "tst_qthread"
+
                        ;; The 'tst_qsystemsemaphore' test sometimes fails.
                        "tst_qsystemsemaphore"
                        ;; The 'tst_moc' test fails with "'fi.exists()' returned FALSE".