.github: Fix capitalization in issue templates (#368493)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -11,7 +11,7 @@ assignees: ''
 
 <!-- A clear and concise description of what the bug is. -->
 
-## Steps To Reproduce
+## Steps to reproduce
 
 Steps to reproduce the behavior:
 

.github/ISSUE_TEMPLATE/build_failure.md

@@ -7,7 +7,7 @@ assignees: ''
 
 ---
 
-## Steps To Reproduce
+## Steps to reproduce
 
 Steps to reproduce the behavior:
 

.github/ISSUE_TEMPLATE/out_of_date_package_report.md

@@ -7,7 +7,7 @@ assignees: ''
 
 ---
 
-## Package Information
+## Package information
 
 <!-- Search for the package here: https://search.nixos.org/packages?channel=unstable -->
 

.github/ISSUE_TEMPLATE/unreproducible_package.md

@@ -31,7 +31,7 @@ Fixing bit-by-bit reproducibility also has additional advantages, such as
 avoiding hard-to-reproduce bugs, making content-addressed storage more effective
 and reducing rebuilds in such systems.
 
-## Steps To Reproduce
+## Steps to reproduce
 
 In the following steps, replace `<package>` with the canonical name of the
 package.