Update the nvm required by the Dashboard (#2984)

PBENCH-891

This PR addresses some of the issues that we've seen recently with the Dashboard unit testing in the CI. This was the result of a breaking change to the tough-cookie component. tough-cookie is not used by the Dashboard; rather, it's a dependency of a dependency of Jest which we use for Dashboard unit testing.

This PR makes three changes:

* Add an explicit (development) dependency on tough-cookie v4.1.2 (the breakage was introduced in v4.1.0, and v4.1.1 was a failed attempt to fix it); without the explicit dependency, we seem to still pick up v4.1.0.

* Add a command to the build script to remove the node_modules directory, to ensure that we pick up a fresh installation of our dependencies. (There are other ways to accomplish this (such as the npm commands, clean-install and ci), but without a version-controlled package-lock.json file, they all present problems, so we'll just brute-force it for now.) Also, since it's not currently version-controlled, remove the package-lock.json file, so that we generate a fresh set of dependencies on each build.

* Remove the dependency on nvm. It pulls a very old version of the manager, and we don't seem to actually need it (at least, as a production dependency...).

build.sh

@@ -19,8 +19,9 @@ if [[ ${GITTOP} =~ "fatal: unsafe repository ('/home/root/pbench'" ]] ; then
 fi
 
 # Install the Dashboard dependencies, including the linter's dependencies and
-# the unit test dependencies.
-( cd dashboard && npm install )
+# the unit test dependencies.  First, remove any existing Node modules and
+# package-lock.json to ensure that we install the latest.
+( cd dashboard && rm -rf node_modules package-lock.json && npm install )
 
 # Test for code style and lint
 black --check .

dashboard/package.json

@@ -22,7 +22,6 @@
     "jest": "^27.5.1",
     "js-cookie": "^3.0.1",
     "less-watch-compiler": "^1.16.3",
-    "nvm": "0.0.4",
     "patternfly": "^3.9.0",
     "react": "^17.0.2",
     "react-app-rewired": "^2.2.1",
@@ -88,6 +87,7 @@
     "jsdoc": "^3.6.10",
     "less": "^4.1.2",
     "less-loader": "^11.0.0",
-    "prettier": "^2.6.2"
+    "prettier": "^2.6.2",
+    "tough-cookie": "^4.1.2"
   }
 }