Prepare v0.73.0 (#1209)

## Google Cloud PHP v0.73.0

### google/cloud-bigquery v1.4.1

* Added documentation for BigQuery job time filter. (#1183)
* Updated tests to conform to linting requirements. (#1192)

### google/cloud-bigquerydatatransfer v0.7.0

* Updated BigQueryDataTransfer generated client. (#1184)

### google/cloud-core v1.22.0

* Updated Symfony Lock Adapter to provide better exception messaging and context. (#1204)
* Added support for custom headers on resumable uploaders. (#1111)
* Updated tests to conform to linting requirements. (#1192)

### google/cloud-datastore v1.5.5

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-debugger v0.12.3

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-error-reporting v0.11.3

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-firestore v0.12.1

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-language v0.15.3

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-logging v1.12.6

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-pubsub v1.4.2

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-spanner v1.6.3

* Fixed a bug which prevented field values from being set to `null`. (#1201)
* Updated tests to conform to linting requirements. (#1192)

### google/cloud-speech v0.16.0

* **BREAKING CHANGE** Removed deprecated v1beta1 client for Cloud Speech and update generated clients. (#1196)
* Updated tests to conform to linting requirements. (#1192)

### google/cloud-storage v1.7.0

* Improve Storage Signed URL support. Added support for CORS headers and improved validation of inputs. (#1111)
* Updated tests to conform to linting requirements. (#1192)

### google/cloud-text-to-speech v0.1.2

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-trace v0.10.3

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-translate v1.2.4

* Updated tests to conform to linting requirements. (#1192)

### google/cloud-vision v0.15.2

* Updated tests to conform to linting requirements. (#1192)

VERSION

@@ -1 +1 @@
-1.2.3
+1.2.4

src/TranslateClient.php

@@ -53,7 +53,7 @@ class TranslateClient
 {
     use ClientTrait;
 
-    const VERSION = '1.2.3';
+    const VERSION = '1.2.4';
 
     const ENGLISH_LANGUAGE_CODE = 'en';