`strip` option preserves inner text of removed tags — request for content-removing option

Start with the process_tag entry point shown in the issue, then inspect get_conv_fn_cached and the existing handling of strip. Verify the provided script, style, and noscript example and confirm that decompose removes both the tags and their child content while preserving surrounding text.

Environment

• markdownify: 1.2.2
• Python: 3.12.3

Current Behavior

strip=["script"] removes the tag but preserves its inner text as plain text:

```python
from markdownify import markdownify as md

html = '

Hello

<script>alert("js noise")</script>

World

'
print(md(html, strip=["script"]))

Hello

alert("js noise") ← script content remains as plain text

World

```

Root Cause

process_tag() collects and joins all child text before checking
should_convert_tag(). By the time get_conv_fn_cached() returns None
for a stripped tag, the child text has already been assembled:

```python
def process_tag(self, node, ...):
# Children processed unconditionally — strip has no effect here
child_strings = [self.process_element(el, ...) for el in children_to_convert]
text = ''.join(child_strings)

# should_convert_tag() checked only here — too late to suppress children
convert_fn = self.get_conv_fn_cached(node.name)  # returns None for stripped tags
if convert_fn is not None:
    text = convert_fn(node, text, ...)

return text  # child text always returned

```

Proposed Solution

Add a decompose parameter that suppresses child processing entirely:

```python
md(html, decompose=["script", "style", "noscript"])

→ Hello\n\nWorld

```

Implementation: early return '' in process_tag when the tag is in the
decompose list.

Workaround

```python
from bs4 import BeautifulSoup
from markdownify import markdownify as md

soup = BeautifulSoup(html, "html.parser")
for tag in soup(["script", "style", "noscript"]):
tag.decompose()
md(str(soup), heading_style="ATX")
```

Use Case

This affects web scraping pipelines where <script> and <style> content
is meaningless as plain text — analytics snippets, minified JS bundles, and
inline CSS all leak into the markdown output when using strip.