Fix chat template test version scrubbing (#6140)

Fixes an issue where versions in package references to just-built packages were not always being scrubbed correctly.

Prior to this PR, specific version suffixes (-ci, -dev) were scrubbed, but this new PR takes a more robust approach that looks for <PackageReference /> items to just-built packages and scrubs the suffix of the Version attribute.

There's a static field _packagePrefixesWithJustBuiltVersionNumber that can be extended with more package prefixes that are expected to have a just-built version number.

If we're willing to be less conservative, we could even go even further and scrub any references to Microsoft.Extensions.* packages.

Fixes #6128

Author: MackinnonBuck

test/ProjectTemplates/Microsoft.Extensions.AI.Templates.IntegrationTests/AichatwebTemplatesTests.cs

@@ -71,7 +71,11 @@ public async Task BasicTest()
                     filePath.EndsWith("aichatweb/aichatweb.csproj.in"))
                 {
                     content.ScrubByRegex("<UserSecretsId>(.*)<\\/UserSecretsId>", "<UserSecretsId>secret</UserSecretsId>");
-                    content.ScrubByRegex("\"(\\d*\\.\\d*\\.\\d*)-(dev|ci)\"", "\"$1\"");
+
+                    // Scrub references to just-built packages and remove the suffix, if it exists.
+                    // This allows the snapshots to remain the same regardless of where the repo is built (e.g., locally, public CI, internal CI).
+                    var pattern = @"(?<=<PackageReference\s+Include=""Microsoft\.Extensions\..*""\s+Version="")(\d+\.\d+\.\d+)(?:-[^""]*)?(?=""\s*/>)";
+                    content.ScrubByRegex(pattern, replacement: "$1");
                 }
 
                 if (filePath.EndsWith("aichatweb/Properties/launchSettings.json"))