Docker: Remove pinned apt versions.

docker/dockerfile

@@ -12,21 +12,21 @@ RUN useradd -u 1000 -U -m -c Jenkins jenkins
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update && \
     apt-get install --no-install-recommends -y \
-        bc=1.07.1-2build1 \
-        build-essential=12.8ubuntu1.1 \
-        curl=7.68.0-1ubuntu2.5 \
-        dos2unix=7.4.0-2 \
-        git=1:2.25.1-1ubuntu3.1 \
-        lib32stdc++6=10.2.0-5ubuntu1~20.04 \
-        mscgen=0.20-12 \
-        p7zip-full=16.02+dfsg-7build1 \
-        python3=3.8.2-0ubuntu2 \
-        python3-pip=20.0.2-5ubuntu1.3 \
-        tar=1.30+dfsg-7ubuntu0.20.04.1 \
-        unzip=6.0-25ubuntu1 \
-        wget=1.20.3-1ubuntu1 \
-        libxml2-utils=2.9.10+dfsg-5 \
-        zip=3.0-11build1 && \
+        bc \
+        build-essential \
+        curl \
+        dos2unix \
+        git \
+        lib32stdc++6 \
+        mscgen \
+        p7zip-full \
+        python3 \
+        python3-pip \
+        tar \
+        unzip \
+        wget \
+        libxml2-utils \
+        zip && \
     apt-get autoremove -y && \
     apt-get autoclean -y && \
     rm -rf /var/lib/apt/lists/*