minor #22913 [Yaml] Deprecate tags using colon (GuilhemN)

This PR was squashed before being merged into the 3.4 branch (closes #22913).

Discussion
----------

[Yaml] Deprecate tags using colon

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no <!-- don't forget updating src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Using a colon in a tag doesn't look like yaml and causes trouble (see symfony/symfony#22878), so I propose to just deprecate these tags in favor of more consistent tags.

```yml
- !php/const:PHP_INT_MAX
- !php/object:O:30:"Symfony\Component\Yaml\Tests\A":1:{s:1:"a";s:3:"foo";}
```
would become
```yml
- !php/const PHP_INT_MAX
- !php/object O:30:"Symfony\Component\Yaml\Tests\A":1:{s:1:"a";s:3:"foo";}
```

Commits
-------

9815af3 [Yaml] Deprecate tags using colon

Tests/Fixtures/yaml/services2.yml

@@ -5,7 +5,7 @@ parameters:
         - false
         - 0
         - 1000.3
-        - !php/const:PHP_INT_MAX
+        - !php/const PHP_INT_MAX
     bar: foo
     escape: '@@escapeme'
     foo_bar: '@foo_bar'

composer.json

@@ -20,7 +20,7 @@
         "psr/container": "^1.0"
     },
     "require-dev": {
-        "symfony/yaml": "~3.3|~4.0",
+        "symfony/yaml": "~3.4|~4.0",
         "symfony/config": "~3.3|~4.0",
         "symfony/expression-language": "~2.8|~3.0|~4.0"
     },
@@ -35,7 +35,7 @@
         "symfony/config": "<3.3.1",
         "symfony/finder": "<3.3",
         "symfony/proxy-manager-bridge": "<3.4",
-        "symfony/yaml": "<3.3"
+        "symfony/yaml": "<3.4"
     },
     "provide": {
         "psr/container-implementation": "1.0"