STCLI-195 pin webpack to ~5.68.0

Oy, the hits just keep coming. It seems that `5.69.0` and `5.70.0` don't
play nice with `moment` and barf thousands of lines of warnings into the
log when running tests, but `5.69.1` isn't compatible with
`karma-webpack` which prevents tests from running _at all_. Yuck.

Refs STCLI-195

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 2.6.0 IN PROGRESS
 
-* Avoid `webpack` > `5.69.1` due to `moment` incompatibilities. Refs STCLI-195.
+* Pin `webpack` to `~5.68.0` due to `moment` and `karma-webpack` trouble. Refs STCLI-195.
 
 ## [2.5.1](https://github.com/folio-org/stripes-cli/tree/v2.5.1) (2022-03-25)
 

package.json

@@ -64,7 +64,7 @@
     "simple-git": "^1.89.0",
     "supports-color": "^4.5.0",
     "update-notifier": "^2.3.0",
-    "webpack": "5.69.1",
+    "webpack": "~5.68.0",
     "webpack-bundle-analyzer": "^4.4.2",
     "yargs": "^13.1.0"
   },