add fedora 34 and ubuntu 21.04 (#4331)

* add fedora 34 and ubuntu 21.04

* remove qt5-default from ubuntu 21.04

apparently it's not required?

* disable tests on fedora 34

.ci/UbuntuHirsute/Dockerfile

@@ -0,0 +1,24 @@
+FROM ubuntu:hirsute
+
+RUN apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+        build-essential \
+        ccache \
+        clang-format \
+        cmake \
+        file \
+        g++ \
+        git \
+        liblzma-dev \
+        libmariadb-dev-compat \
+        libprotobuf-dev \
+        libqt5multimedia5-plugins \
+        libqt5sql5-mysql \
+        libqt5svg5-dev \
+        libqt5websockets5-dev \
+        protobuf-compiler \
+        qtmultimedia5-dev \
+        qttools5-dev \
+        qttools5-dev-tools \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*