Add CredScanSuppressions.json for new findings

Author: akoeplinger

.config/CredScanSuppressions.json

@@ -0,0 +1,9 @@
+{
+    "tool": "Credential Scanner",
+    "suppressions": [
+        {
+            "_justification": "Upstream code and these are supposed to be public passwords.",
+            "file": "flang/docs/GettingInvolved.md"
+        }
+    ]
+}

eng/azure-pipelines.yml

@@ -91,6 +91,8 @@ extends:
         name: $(DncEngInternalBuildPool)
         image: 1es-windows-2022
         os: windows
+      credscan:
+        suppressionsFile: $(Build.SourcesDirectory)/.config/CredScanSuppressions.json
     containers:
       mariner2crossamd64:
         image: mcr.microsoft.com/dotnet-buildtools/prereqs:cbl-mariner-2.0-cross-amd64