CI/Coverity: Do not build QEMU, SeaBIOS or OVMF

Such external projects should have their own Coverity runs, and
there's not much point in also making them part of our scan (apart
from greatly increasing the amount of code scanned).

Trim the dependencies now that QEMU is not built.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

.github/workflows/coverity.yml

@@ -11,15 +11,13 @@ jobs:
     steps:
     - name: Install build dependencies
       run: |
-        sudo apt-get install -y wget git bcc bin86 gawk bridge-utils \
-          iproute2 libcurl4-openssl-dev bzip2 libpci-dev build-essential \
-          make gcc libc6-dev libc6-dev-i386 linux-libc-dev zlib1g-dev \
-          libncurses5-dev patch libvncserver-dev libssl-dev libsdl-dev iasl \
-          libbz2-dev e2fslibs-dev git-core uuid-dev ocaml libx11-dev \
-          ocaml-findlib xz-utils libyajl-dev libpixman-1-dev \
-          libaio-dev libfdt-dev cabextract libglib2.0-dev autoconf automake \
-          libtool libfuse-dev liblzma-dev ninja-build \
-          kpartx python3-dev golang python-dev libsystemd-dev
+        sudo apt-get install -y wget git gawk bridge-utils \
+          iproute2 bzip2 build-essential \
+          make gcc zlib1g-dev libncurses5-dev iasl \
+          libbz2-dev e2fslibs-dev git-core uuid-dev ocaml \
+          ocaml-findlib xz-utils libyajl-dev \
+          autoconf libtool liblzma-dev \
+          python3-dev golang python-dev libsystemd-dev
 
     - uses: actions/checkout@v2
       with:
@@ -27,11 +25,13 @@ jobs:
 
     - name: Configure Xen
       run: |
-        ./configure
+        ./configure --with-system-qemu=/bin/true \
+                    --with-system-seabios=/bin/true \
+                    --with-system-ovmf=/bin/true
 
     - name: Pre build stuff
       run: |
-        make -C tools/firmware/etherboot all && make mini-os-dir
+        make mini-os-dir
 
     - uses: vapier/coverity-scan-action@v1
       with: