chore(deps): update dependency google-auth-oauthlib to v0.4.1 [(#2797)](

GoogleCloudPlatform/python-docs-samples#2797)

* chore(deps): update dependency google-auth-oauthlib to v0.4.1

* resolve dependency finding errors

* fix new matplotlib error

Co-authored-by: Leah E. Cole <[email protected]>
Co-authored-by: Leah Cole <[email protected]>
Co-authored-by: Bu Sun Kim <[email protected]>
Co-authored-by: Christopher Wilcox <[email protected]>