🐛 fix unexpected run of release workflow (#9494)

I have discovered a bug located within `.github/workflows/_release.yml`
which is the primary cause of continuous integration (CI) errors. The
problem can be solved; therefore, I have constructed a PR to address the
issue.

## The Issue

Access the following link to view the exact errors: [Langhain Release
Workflow](https://github.com/langchain-ai/langchain/actions/workflows/langchain_release.yml)

The instances of these errors take place for **each PR** that updates
`pyproject.toml`, excluding those specifically associated with bumping
PRs.

See below for the specific error message:

```
Error: Error 422: Validation Failed: {"resource":"Release","code":"already_exists","field":"tag_name"}
```

An image of the error can be viewed here:

![Image](https://github.com/langchain-ai/langchain/assets/13769670/13125f73-9b53-49b7-a83e-653bb01a1da1)

The `_release.yml` document contains the following if-condition:

```yaml
    if: |
        ${{ github.event.pull_request.merged == true }}
        && ${{ contains(github.event.pull_request.labels.*.name, 'release') }}
```

## The Root Cause

The above job constantly runs as the `if-condition` is always identified
as `true`.

## The Logic

The `if-condition` can be defined as `if: ${{ b1 }} && ${{ b2 }}`, where
`b1` and `b2` are boolean values. However, in terms of condition
evaluation with GitHub Actions, `${{ false }}` is identified as a string
value, thereby rendering it as truthy as per the [official
documentation](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idif).

I have run some tests regarding this behavior within my forked
repository. You can consult my [debug
PR](https://github.com/zawakin/langchain/pull/1) for reference.

Here is the result of the tests:

|If-Condition|Outcome|
|:--:|:--:|
|`if: true && ${{ false }}`|Execution|
|`if: ${{ false }}` |Skipped|
|`if: true && false` |Skipped|
|`if: false`|Skipped|
|`if: ${{ true && false }}` |Skipped|

In view of the first and second results, we can infer that `${{ false
}}` can only be interpreted as `true` for conditions composed of some
expressions.
It is consistent that the condition of `if: ${{ inputs.working-directory
== 'libs/langchain' }}` works.

It is surprised to be skipped for the second case but it seems the spec
of GitHub Actions 😓

Anyway, the PR would fix these errors, I believe 👍 

Could you review this? @hwchase17 or @shoelsch , who is the author of
[PR](https://github.com/langchain-ai/langchain/pull/360).

.github/workflows/_release.yml

@@ -14,8 +14,8 @@ env:
 jobs:
   if_release:
     if: |
-        ${{ github.event.pull_request.merged == true }}
-        && ${{ contains(github.event.pull_request.labels.*.name, 'release') }}
+        github.event.pull_request.merged == true
+        && contains(github.event.pull_request.labels.*.name, 'release')
     runs-on: ubuntu-latest
     defaults:
       run: