Backport of use go 1.21.7 into release/1.17.x (#20559)

* backport of commit 6c31fd76

* backport of commit 8620e735



---------

Co-authored-by: skpratt <sarah.pratt@hashicorp.com>

.changelog/20545.txt

+```release-note:improvement
+Upgrade to use Go 1.21.7.
+```
\ No newline at end of file

.go-version

-1.21.6
+1.21.7