fix(release): add minor step to internal release create command (#64377)

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This PR adds the ability to use `--type minor` when running `sg release
create` during the release process.

For the time being this step is the _same_ as `--type patch` which is
the default, however this allows us to differentiate the two types now
and prepares for when/if the two types diverge. This also clears up the
some confusion as the `sg release` command _can_ accept `--type minor`
already and one would expect that to be the choice when you are in fact
cutting a minor type.

Closes:
https://linear.app/sourcegraph/issue/REL-351/sourcegraphsourcegraph64377-fixrelease-add-minor-step-to-internal

## Test plan

Tested locally with `--type minor` tag.

```shell
➜  sourcegraph git:(08-08-jdp_release_minor-flag-addition) sg release create --version 5.6.877 --type minor
👉 [     setup] Finding release manifest in "."
   [     setup] No explicit branch name was provided, assuming current branch is the target: 08-08-jdp_release_minor-flag-addition
   [     setup] Found manifest for "sourcegraph" (github.com/sourcegraph/sourcegraph)
   [      meta] Owners: @sourcegraph/release
   [      meta] Repository: github.com/sourcegraph/sourcegraph
👉 [      vars] Variables
   [      vars] version="v5.6.877"
   [      vars] tag="5.6.877"
   [      vars] config="{\"version\":\"v5.6.877\",\"inputs\":\"\",\"type\":\"minor\"}"
   [      vars] git.branch="08-08-jdp_release_minor-flag-addition"
   [      vars] is_development="false"
.... Stuff here
   [ buildkite] Build created, see:
   [ buildkite] "https://buildkite.com/sourcegraph/sourcegraph/builds/287192"
   [      step] Step "buildkite" succeeded
```

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## Changelog

Internal change, N/A

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release.yaml

@@ -51,6 +51,32 @@ internal:
               echo "Build created, see:"
               echo $body | jq .web_url
             fi
+      minor:
+        - name: 'buildkite'
+          cmd: |
+            echo "Triggering build on sourcegraph/sourcegraph with VERSION={{version}} on branch {{git.branch}}"
+            body=$(wget --content-on-error -O- --header="Content-Type: application/json" --header="Authorization: Bearer $BUILDKITE_ACCESS_TOKEN" --post-data '{
+              "commit": "HEAD",
+              "branch": "{{git.branch}}",
+              "message": "Internal release build for {{version}}",
+              "env": {
+                    "RELEASE_INTERNAL": "true",
+                    "VERSION": "{{tag}}",
+                    "IS_DEVELOPMENT_RELEASE": "{{is_development}}"
+              }
+            }' https://api.buildkite.com/v2/organizations/sourcegraph/pipelines/sourcegraph/builds)
+            exit_code=$?
+
+            if [ $exit_code != 0 ]; then
+              echo "❌ Failed to create build on Buildkite, got:"
+              echo "--- raw body ---"
+              echo $body
+              echo "--- raw body ---"
+              exit $exit_code
+            else
+              echo "Build created, see:"
+              echo $body | jq .web_url
+            fi
   finalize:
     steps:
       - name: 'Register on release registry'