Fix environment variables that are not yet available (#5113)

[Preview](https://docs-getdbt-com-git-dbeatty10-patch-2-dbt-labs.vercel.app/reference/global-configs/about-global-configs#available-flags)

## What are you changing in this pull request and why?

See #5111

These two things are not accurate:

1. `DBT_TARGET` won't be available until [dbt-core
#9081](dbt-labs/dbt-core#9081) is
merged+released
1. `DBT_PROFILE` won't be available until [dbt-core
#9081](dbt-labs/dbt-core#9081) is
merged+released

So this PR just removes those environment variable names until then.

## 🎩 

After the fix:

<img width="600" alt="image"
src="https://github.com/dbt-labs/docs.getdbt.com/assets/44704949/8ffdf967-604d-4686-ab4b-0e295dfea7a0">

...

<img width="600" alt="image"
src="https://github.com/dbt-labs/docs.getdbt.com/assets/44704949/0e522215-d8be-48ce-bb54-d2568e2e9479">

...

<img width="600" alt="image"
src="https://github.com/dbt-labs/docs.getdbt.com/assets/44704949/d58129d0-44c2-481e-a8bb-274fd1276c90">


## To do

- [x] Wait for #5112 to
be merged

## Checklist
- [x] Review the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.

website/docs/reference/global-configs/about-global-configs.md

@@ -78,7 +78,7 @@ Because the values of `flags` can differ across invocations, we strongly advise
 | [populate_cache](/reference/global-configs/cache) | boolean | True | ✅ | `DBT_POPULATE_CACHE` | `--populate-cache`, `--no-populate-cache` | ✅ |
 | [print](/reference/global-configs/print-output#suppress-print-messages-in-stdout) | boolean | True | ❌ | `DBT_PRINT` | `--print` | ❌ |
 | [printer_width](/reference/global-configs/print-output#printer-width) | int | 80 | ✅ | `DBT_PRINTER_WIDTH` | `--printer-width` | ❌ |
-| [profile](/docs/core/connect-data-platform/connection-profiles#about-profiles) | string | None | ✅ (as top-level key) | `DBT_PROFILE` | `--profile` | ❌ |
+| [profile](/docs/core/connect-data-platform/connection-profiles#about-profiles) | string | None | ✅ (as top-level key) |  | `--profile` | ❌ |
 | [profiles_dir](/docs/core/connect-data-platform/connection-profiles#about-profiles) | path | None (current dir, then HOME dir) | ❌ | `DBT_PROFILES_DIR` | `--profiles-dir` | ❌ |
 | [project_dir](/reference/dbt_project.yml) | path |  | ❌ | `DBT_PROJECT_DIR` | `--project-dir` | ❌ |
 | [quiet](/reference/global-configs/logs#suppress-non-error-logs-in-output) | boolean | False | ❌ | `DBT_QUIET` | `--quiet` | ✅ |
@@ -88,7 +88,7 @@ Because the values of `flags` can differ across invocations, we strongly advise
 | [static_parser](/reference/global-configs/parsing#static-parser) | boolean | True | ✅ | `DBT_STATIC_PARSER` | `--static-parser`, `--no-static-parser` | ❌ |
 | [store_failures](/reference/resource-configs/store_failures) | boolean | False | ✅ (as resource config) | `DBT_STORE_FAILURES` | `--store-failures`, `--no-store-failures` | ✅ |
 | [target_path](/reference/global-configs/json-artifacts) | path | None (uses `target/`) | ❌ | `DBT_TARGET_PATH` | `--target-path` | ❌ |
-| [target](/docs/core/connect-data-platform/connection-profiles#about-profiles) | string | None | ❌ | `DBT_TARGET` | `--target` | ❌ |
+| [target](/docs/core/connect-data-platform/connection-profiles#about-profiles) | string | None | ❌ |  | `--target` | ❌ |
 | [use_colors_file](/reference/global-configs/logs#color) | boolean | True | ✅ | `DBT_USE_COLORS_FILE` | `--use-colors-file`, `--no-use-colors-file` | ❌ |
 | [use_colors](/reference/global-configs/print-output#print-color) | boolean | True | ✅ | `DBT_USE_COLORS` | `--use-colors`, `--no-use-colors` | ❌ |
 | [use_experimental_parser](/reference/global-configs/parsing#experimental-parser) | boolean | False | ✅ | `DBT_USE_EXPERIMENTAL_PARSER` | `--use-experimental-parser`, `--no-use-experimental-parser` | ❌ |