Enable no-fallthrough ESLint rule

extensions/ql-vscode/.eslintrc.js

@@ -57,7 +57,6 @@ const baseConfig = {
     "func-style": "off",
     "i18n-text/no-en": "off",
     "no-invalid-this": "off",
-    "no-fallthrough": "off",
     "no-console": "off",
     "no-shadow": "off",
     "github/array-foreach": "off",

extensions/ql-vscode/src/codeql-cli/cli.ts

@@ -1532,7 +1532,7 @@ export class CodeQLCliServer implements Disposable {
     const distribution = await this.distributionProvider.getDistribution();
     switch (distribution.kind) {
       case FindDistributionResultKind.CompatibleDistribution:
-
+      // eslint-disable-next-line no-fallthrough -- Intentional fallthrough
       case FindDistributionResultKind.IncompatibleDistribution:
         return distribution.version;