chore(.github): delete issue templates in favor of default ones

Default issue templates can be found in https://github.com/falcosecurity/.github repo.

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

.github/ISSUE_TEMPLATE/bug-report.md

@@ -1,28 +0,0 @@
----
-name: Bug Report
-about: Report a bug encountered while operating Falco
-labels: kind/bug
-
----
-
-<!-- Please use this template while reporting a bug and provide as much info as possible. Not doing so may result in your bug not being addressed in a timely manner. Thanks!
-
-If the matter is security related, please disclose it privately via https://falco.org/security/
--->
-
-**What happened**:
-
-**What you expected to happen**:
-
-**How to reproduce it (as minimally and precisely as possible)**:
-
-**Anything else we need to know?**:
-
-**Environment**:
-- Falco version (use `falco --version`):
-- System info <!-- Falco has a built-in support command you can use  "falco --support | jq .system_info" -->
-- Cloud provider or hardware configuration:
-- OS (e.g: `cat /etc/os-release`):
-- Kernel (e.g. `uname -a`):
-- Install tools (e.g. in kubernetes, rpm, deb, from source):
-- Others:

.github/ISSUE_TEMPLATE/enhancement.md

@@ -1,11 +0,0 @@
----
-name: Enhancement Request
-about: Suggest an enhancement to the Falco project
-labels: kind/feature
-
----
-<!-- Please only use this template for submitting enhancement requests -->
-
-**What would you like to be added**:
-
-**Why is this needed**:

.github/ISSUE_TEMPLATE/failing-tests.md

@@ -1,20 +0,0 @@
----
-name: Failing Test
-about: Report test failures in Falco CI jobs
-labels: kind/failing-test
-
----
-
-<!-- Please only use this template for submitting reports about failing tests in Falco CI jobs -->
-
-**Which jobs are failing**:
-
-**Which test(s) are failing**:
-
-**Since when has it been failing**:
-
-**Test link**:
-
-**Reason for failure**:
-
-**Anything else we need to know**: