Remove .lgtm.yml

lgtm.com is part of GitHub and the original service has shut down.

Change-Id: I03f109408cd408811c60fffdaac42eaeb8c9a84c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Dimitrios Apostolou <jimis@qt.io>

.lgtm.yml

@@ -1,33 +0,0 @@
-extraction:
-  cpp:
-    prepare:
-      packages:
-        - libgl-dev
-        - libglu-dev
-        - libpcre2-dev
-        - libz-dev
-        - libfreetype6-dev
-        - libpng-dev
-        - libjpeg-dev
-        - libsqlite3-dev
-    after_prepare:
-      - mkdir $HOME/cmake-3.17 \
-          \ && wget -qO- "https://cmake.org/files/v3.17/cmake-3.17.3-Linux-x86_64.tar.gz" \
-            \ | tar -xzf - --strip-components=1 -C $HOME/cmake-3.17
-      - export PATH=$HOME/cmake-3.17/bin:$PATH
-
-    # Pre-analysis step.
-    configure:
-      command:
-        - "./configure -cmake -opensource -confirm-license -debug -no-pch \
-          \ -nomake tests -nomake examples -no-harfbuzz \
-          \ -system-pcre -system-zlib -system-freetype -system-libpng \
-          \ -system-libjpeg -system-sqlite"
-        # We skip analyzing the bootstrap library, since the same code is
-        # built with non-standard flags and false-positives are flagged.
-        - ninja bootstrap_tools
-
-    # Actual analysis.
-    index:
-      build_command:
-        - ninja