Add SLES 15 SP6 with non-blocking tests in CI

SLES 15 SP6 and Opensuse 15.6 seem to need direct configuration
for git and curl to take CA certificates into use. [CI Platforms]

nodejs18:
  - Needed for QtWebEngine build done in RTA
  - But nodejs18 doesn't yet have a provider
  - Therefore using commonly installed nodejs 18.6.0 as it's available

Task-number: QTQAINFRA-6746
Task-number: QTQAINFRA-6745
Change-Id: I73fb2a98a648f56b7330e26811e6d4780c51ab80
Reviewed-by: Heikki Halmet <heikki.halmet@qt.io>

coin/platform_configs/cmake_platforms.yaml

@@ -139,6 +139,16 @@ Configurations:
         'CMAKE_ARGS=-DOPENSSL_ROOT_DIR={{.Env.OPENSSL_HOME}}',
         'NON_QTBASE_CMAKE_ARGS=-DFFMPEG_DIR={{.Env.FFMPEG_DIR}}'
     ]
+-
+    Id: 'sles-15_sp6-static'
+    Template: 'qtci-linux-SLES-15_SP6-x86_64-51'
+    Compiler: 'GCC'
+    Features: ['Sccache', 'DisableTests', 'UseConfigure', 'GenerateSBOM', 'VerifySBOM']
+    Configure arguments: '-nomake examples -static -no-sql-db2 -no-sql-ibase -no-sql-mysql -no-sql-oci -no-sql-psql -no-sql-mimer'
+    Environment variables: [
+        'CMAKE_ARGS=-DOPENSSL_ROOT_DIR={{.Env.OPENSSL_HOME}}',
+        'NON_QTBASE_CMAKE_ARGS=-DFFMPEG_DIR={{.Env.FFMPEG_DIR}}'
+    ]
 -
     Id: 'windows-10_22h2-msvc2022'
     Template: 'qtci-windows-10_22H2-x86_64-52'