Prepare v0.82.0 (#1337)
Prepare v0.82.0 (#1337)

## Google Cloud PHP v0.82.0

### google/cloud-bigquery v1.4.5

* Remove unnecessary ternary expression (#1327)
* Use dedicated PHPUnit assertions (#1331)

### google/cloud-core v1.23.7

* Use combined assignment operators when possible (#1328)
* Remove unused variables passed to closures (#1330)

### google/cloud-datastore v1.5.10

* Use combined assignment operators when possible (#1328)
* Use dedicated PHPUnit assertions (#1331)

### google/cloud-debugger v0.14.2

* Remove unused variables passed to closures (#1330)
* Use dedicated PHPUnit assertions (#1331)

### google/cloud-firestore v0.15.3

* Fix handling of empty sets in Firestore updates (#1316)
* Remove auxiliary variables when they are return right away (#1329)

### google/cloud-spanner v1.11.0

* Use combined assignment operators when possible (#1328)
* Remove unused variables passed to closures (#1330)
* Add support for DML and Partitioned DML (#1309)

### google/cloud-storage v1.9.1

* Use dedicated PHPUnit assertions (#1331)

### google/cloud-vision v0.17.2

* Use dedicated PHPUnit assertions (#1331)

googleapis/google-cloud-php-core