Bumped the Golang version to 1.19 in pre-requisite documentation (#6386)

* Corrected Golang version to 1.19

Go.mod is using golang 1.19 and pre-requisite is using 1.18. So Incrementing the developer guide to meet the golang version.

Signed-off-by: Uday Kumar <[email protected]>

* Adding changelog/fragments for go lang version change

Signed-off-by: Uday Kumar <[email protected]>

---------

Signed-off-by: Uday Kumar <[email protected]>
Co-authored-by: Uday Kumar <[email protected]>

Author: ukumar009

changelog/fragments/docs-bump-go-version.yaml

@@ -0,0 +1,12 @@
+entries:
+  - description: >
+      (docs) Update the go version in the developer guide.  The documentation wasn't updated when the go version was bumped to v1.19.
+    # kind is one of:
+    # - addition
+    # - change
+    # - deprecation
+    # - removal
+    # - bugfix
+    kind: "bugfix"
+    # Is this a breaking change?
+    breaking: false

website/content/en/docs/contribution-guidelines/developer-guide.md

@@ -9,7 +9,7 @@ weight: 1
 ### Prerequisites
 
 - [git][git-tool]
-- [go][go-tool] version 1.18
+- [go][go-tool] version 1.19
 
 ### Download Operator SDK