terraform-provider-postgresql: Update to 1.21.0

Changes:
v1.21.0
* Make function security, strictness, volatility, and parallel safety
  configurable
* Bump gocloud dependency to fix aws CA validation
* Allow for inlining client cert
* Use uint32 for OID to stop conversion errors with pguint32
* Postgresql 15 support
* Added MS Azure passwordless authentication
* Add 'Injecting credentials' section to provider docs
* fixed escaping for postgresql user info

v1.20.0
As this is my first release for this project, I am keeping the changes
to a minimum until I am more comfortable with the release process.

* Bump `go` to `1.20`
* Bump `lib/pq` to `1.10.9`
* Perform `db.Ping()` during database connection to catch issues earlier

v1.19.0
No change available.

v1.18.0
* New resource: `postgresql_server` and `postgresql_user_mapping`
* New resource: `postgresql_subscription`
* Allow to configure AWS Region with AWS IAM Auth
* Create temporary file for `GOOGLE_APPLICATION_CREDENTIALS` in
  Terraform cloud
* `postgresql_grant`: Concurrency issue on database privileges
  [#224](https://github.com/cyrilgdn/terraform-provider-postgresql/pull/224)
* `postgresql_grant`: Remove `TEMP` privileges for database

v1.17.1
* Missing err check that leads to segfault

[For other releases no changes are available but mostly new resources
and data sources.]

terraform-provider-postgresql/Makefile

@@ -1,6 +1,6 @@
 # $NetBSD$
 
-DISTNAME=	terraform-provider-postgresql-1.11.2
+DISTNAME=	terraform-provider-postgresql-1.21.0
 CATEGORIES=	net
 MASTER_SITES=	${MASTER_SITE_GITHUB:=cyrilgdn/}
 GITHUB_TAG=	v${PKGVERSION_NOREV}