Remove Google and Bing cache examples (#1261)

It seems Bing has also retired their cache functionality 😞
https://x.com/BingWMC/status/1866942204910112957

Signed-off-by: kingthorin <kingthorin@users.noreply.github.com>

Author: kingthorin

document/4-Web_Application_Security_Testing/01-Information_Gathering/01-Conduct_Search_Engine_Discovery_Reconnaissance_for_Information_Leakage.md

@@ -60,19 +60,6 @@ site:owasp.org
 ![Google Site Operation Search Result Example](images/Google_site_Operator_Search_Results_Example_20200406.png)\
 *Figure 4.1.1-1: Google Site Operation Search Result Example*
 
-### Viewing Cached Content
-
-To search for content that has previously been indexed, use the `cache:` operator. This is helpful for viewing content that may have changed since the time it was indexed, or that may no longer be available. Not all search engines provide cached content to search; the most useful source at time of writing is Google.
-
-To view `owasp.org` as it is cached, the syntax is:
-
-```text
-cache:owasp.org
-```
-
-![Google Cache Operation Search Result Example](images/Google_cache_Operator_Search_Results_Example_20200406.png)\
-*Figure 4.1.1-2: Google Cache Operation Search Result Example*
-
 #### Internet Archive Wayback Machine
 
 The [Internet Archive Wayback Machine](https://archive.org/web/) is the most comprehensive tool for viewing historical snapshots of web pages. It maintains an extensive archive of web pages dating back to 1996.
@@ -86,11 +73,6 @@ https://web.archive.org/web/*/owasp.org
 
 This will display a calendar view showing all available snapshots of the site over time.
 
-#### Bing Cache
-
-Bing still provides cached versions of web pages. To view cached content, use the `cache:` operator:
-Alternatively, click the arrow next to search results in Bing and select "Cached" from the dropdown menu.
-
 #### Other Cached Content Services
 
 Additional services for viewing cached or archived web pages include: